1.
Keyboard shortcut
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In computing, a keyboard shortcut is a series of one or several keys that invoke a software or operating system operation when triggered by the user. The meaning of term keyboard shortcut can vary depending on software manufacturer, keyboard shortcuts are generally used to expedite common operations by reducing input sequences to a few keystrokes, hence the term shortcut. To differentiate from general keyboard input, most keyboard shortcuts require the user to press, unmodified key presses are sometimes accepted when the keyboard is not used for general input - such as with graphics packages e. g. Adobe Photoshop or IBM Lotus Freelance Graphics. Other keyboard shortcuts use function keys that are dedicated for use in shortcuts, for simultaneous keyboard shortcuts, one usually first holds down the modifier key, then quickly presses and releases the regular key, and finally releases the modifier key. This distinction is important, as trying to all the keys simultaneously will frequently either miss some of the modifier keys. Sequential shortcuts usually involve pressing and releasing a dedicated key, such as the Esc key. Mnemonics are distinguishable from keyboard shortcuts, in most GUIs, a programs keyboard shortcuts are discoverable by browsing the programs menus – the shortcut is indicated next to the menu choice. There are keyboards that have the shortcuts for an application already marked on them. These keyboards are used for editing video, audio, or graphics. There are also stickers with shortcuts printed on them that can be applied to a regular keyboard, reference cards intended to be propped up in the users workspace also exist for many applications. This highlights a difference in philosophy regarding shortcuts, some systems, typically end-user-oriented systems such as Mac OS or Windows, consider standardized shortcuts essential to the environments ease of use. These systems usually limit a users ability to change shortcuts, possibly even requiring a separate or third-party utility to perform the task, other systems, typically Unix and related, consider shortcuts to be a users prerogative, and that they should be changeable to suit individual preference. For Microsoft Windows, multiple software programs exist like Hotkeycontrol which allow deeper customization of keyboard shortcuts performing advanced tasks, the motivations for customizing key bindings vary. Users new to a program or software environment may customize the new environments keybindings to be similar to another environment with which they are more familiar. More advanced users may customize key bindings to better suit their workflow, adding shortcuts for their commonly used actions, hardcore gamers often customize their key bindings in order to increase performance via faster reaction times. The original Macintosh User Interface Guidelines defined a set of keyboard shortcuts that would remain consistent across application programs and this provides a better user experience than the situation then prevalent of applications using the same keys for different functions. This could result in user errors if one program used ⌘ Command+D to mean Delete while another used it to Duplicate an item, Help Later environments such as Microsoft Windows retain some of these bindings, while adding their own from alternate standards like Common User Access. The simplest keyboard shortcuts consist of one key
2.
Computing
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Computing is any goal-oriented activity requiring, benefiting from, or creating a mathematical sequence of steps known as an algorithm — e. g. through computers. The field of computing includes computer engineering, software engineering, computer science, information systems, the ACM Computing Curricula 2005 defined computing as follows, In a general way, we can define computing to mean any goal-oriented activity requiring, benefiting from, or creating computers. For example, an information systems specialist will view computing somewhat differently from a software engineer, regardless of the context, doing computing well can be complicated and difficult. Because society needs people to do computing well, we must think of computing not only as a profession, the fundamental question underlying all computing is What can be automated. The term computing is also synonymous with counting and calculating, in earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. Computing is intimately tied to the representation of numbers, but long before abstractions like the number arose, there were mathematical concepts to serve the purposes of civilization. These concepts include one-to-one correspondence, comparison to a standard, the earliest known tool for use in computation was the abacus, and it was thought to have been invented in Babylon circa 2400 BC. Its original style of usage was by lines drawn in sand with pebbles, abaci, of a more modern design, are still used as calculation tools today. This was the first known computer and most advanced system of calculation known to date - preceding Greek methods by 2,000 years. The first recorded idea of using electronics for computing was the 1931 paper The Use of Thyratrons for High Speed Automatic Counting of Physical Phenomena by C. E. Wynn-Williams. Claude Shannons 1938 paper A Symbolic Analysis of Relay and Switching Circuits then introduced the idea of using electronics for Boolean algebraic operations, a computer is a machine that manipulates data according to a set of instructions called a computer program. The program has a form that the computer can use directly to execute the instructions. The same program in its source code form, enables a programmer to study. Because the instructions can be carried out in different types of computers, the execution process carries out the instructions in a computer program. Instructions express the computations performed by the computer and they trigger sequences of simple actions on the executing machine. Those actions produce effects according to the semantics of the instructions, computer software or just software, is a collection of computer programs and related data that provides the instructions for telling a computer what to do and how to do it. Software refers to one or more programs and data held in the storage of the computer for some purposes. In other words, software is a set of programs, procedures, algorithms, program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software
3.
User interface
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The user interface, in the industrial design field of human–computer interaction, is the space where interactions between humans and machines occur. Examples of this concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology. Generally, the goal of user interface design is to produce a user interface makes it easy, efficient. This generally means that the needs to provide minimal input to achieve the desired output. Other terms for user interface are man–machine interface and when the machine in question is a computer human–computer interface, the user interface or human–machine interface is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of the part of the Human Machine Interface which we can see. In complex systems, the interface is typically computerized. The term human–computer interface refers to this kind of system, in the context of computing the term typically extends as well to the software dedicated to control the physical elements used for human-computer interaction. The engineering of the interfaces is enhanced by considering ergonomics. The corresponding disciplines are human factors engineering and usability engineering, which is part of systems engineering, tools used for incorporating human factors in the interface design are developed based on knowledge of computer science, such as computer graphics, operating systems, programming languages. Nowadays, we use the graphical user interface for human–machine interface on computers. There is a difference between a user interface and an interface or a human–machine interface. A human-machine interface is typically local to one machine or piece of equipment, an operator interface is the interface method by which multiple equipment that are linked by a host control system is accessed or controlled. The system may expose several user interfaces to serve different kinds of users, for example, a computerized library database might provide two user interfaces, one for library patrons and the other for library personnel. The user interface of a system, a vehicle or an industrial installation is sometimes referred to as the human–machine interface. HMI is a modification of the original term MMI, in practice, the abbreviation MMI is still frequently used although some may claim that MMI stands for something different now. Another abbreviation is HCI, but is commonly used for human–computer interaction
4.
Directory (computing)
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In computing, a directory is a file system cataloging structure which contains references to other computer files, and possibly other directories. On many computers, directories are known as folders, or drawers to provide some relevancy to a workbench or the traditional office file cabinet, files are organized by storing related files in the same directory. In a hierarchical filesystem, a directory contained inside another directory is called a subdirectory, the terms parent and child are often used to describe the relationship between a subdirectory and the directory in which it is cataloged, the latter being the parent. The top-most directory in such a filesystem, which not have a parent of its own, is called the root directory. In modern systems, a directory can contain a mix of files and subdirectories, a reference to a location in a directory system is called a path. In many operating systems, programs have an associated working directory in which they execute, typically, file names accessed by the program are assumed to reside within this directory if the file names are not specified with an explicit directory name. Some operating systems restrict a users access to only their home directory or project directory, in early versions of Unix the root directory was the home directory of the root user, but modern Unix usually uses another directory such as /root for this purpose. In keeping with Unix philosophy, Unix systems treat directories as a type of file, folders are often depicted with icons which visually resemble physical file folders. There is a difference between a directory, which is a file system concept, and the user interface metaphor that is used to represent it. Many operating systems also have the concept of smart folders that reflect the results of a file system search or other operation and these folders do not represent a directory in the file hierarchy. Many email clients allow the creation of folders to organize email and these folders have no corresponding representation in the filesystem structure. If one is referring to a container of documents, the folder is more appropriate. The term directory refers to the way a structured list of document files, operating systems that support hierarchical filesystems implement a form of caching to RAM of recent path lookups. In the Unix world, this is usually called Directory Name Lookup Cache, for local filesystems, DNLC entries normally expire only under pressure from other more recent entries. For network file systems a coherence mechanism is necessary to ensure that entries have not been invalidated by other clients, definition of directory by The Linux Information Project
5.
Command-line interface
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A program which handles the interface is called a command language interpreter or shell. The interface is implemented with a command line shell, which is a program that accepts commands as text input. Command-line interfaces to computer operating systems are widely used by casual computer users. Alternatives to the line include, but are not limited to text user interface menus, keyboard shortcuts. Examples of this include the Windows versions 1,2,3,3.1, and 3.11, DosShell, and Mouse Systems PowerPanel. Command-line interfaces are preferred by more advanced computer users, as they often provide a more concise. Programs with command-line interfaces are generally easier to automate via scripting, a program that implements such a text interface is often called a command-line interpreter, command processor or shell. Under most operating systems, it is possible to replace the shell program with alternatives, examples include 4DOS for DOS, 4OS2 for OS/2. For example, the default Windows GUI is a program named EXPLORER. EXE. These programs are shells, but not CLIs, application programs may also have command line interfaces. When a program is launched from an OS command line shell, interactive command line sessions, After launch, a program may provide an operator with an independent means to enter commands in the form of text. OS inter-process communication, Most operating systems support means of inter-process communication, Command lines from client processes may be redirected to a CLI program by one of these methods. Some applications support only a CLI, presenting a CLI prompt to the user, Some examples of CLI-only applications are, DEBUG Diskpart Ed Edlin Fdisk Ping Some computer programs support both a CLI and a GUI. In some cases, a GUI is simply a wrapper around a separate CLI executable file, in other cases, a program may provide a CLI as an optional alternative to its GUI. CLIs and GUIs often support different functionality, for example, all features of MATLAB, a numerical analysis computer program, are available via the CLI, whereas the MATLAB GUI exposes only a subset of features. The early Sierra games, like the first three Kings Quest games, used commands from a command line to move the character around in the graphic window. Early computer systems often used teleprinter machines as the means of interaction with a human operator, the computer became one end of the human-to-human teleprinter model. So instead of a human communicating with another human over a teleprinter, in time, the actual mechanical teleprinter was replaced by a glass tty, and then by a smart terminal
6.
Desktop environment
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The desktop environment was seen mostly on personal computers until the rise of mobile computing. Desktop GUIs help the user to access and edit files. Instead, the traditional command-line interface is used when full control over the operating system is required. A desktop environment typically consists of icons, windows, toolbars, folders, wallpapers, a GUI might also provide drag and drop functionality and other features that make the desktop metaphor more complete. While the term desktop environment originally described a style of user interfaces following the desktop metaphor and this usage has been popularized by projects such as the Common Desktop Environment, K Desktop Environment, and GNOME. On a system offers a desktop environment, a window manager in conjunction with applications written using a widget toolkit are generally responsible for most of what the user sees. The window manager supports the user interactions with the environment, while the toolkit provides developers a software library for applications with a unified look, a windowing system of some sort generally interfaces directly with the underlying operating system and libraries. This provides support for hardware, pointing devices, and keyboards. The window manager generally runs on top of this windowing system, applications that are created with a particular window manager in mind usually make use of a windowing toolkit, generally provided with the operating system or window manager. A windowing toolkit gives applications access to widgets that allow the user to interact graphically with the application in a consistent way, the first desktop environment was created by Xerox and was sold with the Xerox Alto in the 1970s. The Alto was generally considered by Xerox to be an office computer, it failed in the marketplace because of poor marketing. With the Lisa, Apple introduced a desktop environment on a personal computer. The desktop metaphor was popularized on commercial personal computers by the original Macintosh from Apple in 1984, Microsoft Windows dominates in marketshare among personal computers with a desktop environment. Among the more popular of these are Googles Chromebooks and Chromeboxes, Intels NUC, on tablets and smartphones, the situation is the opposite, with Unix-like operating systems dominating the market, including the iOS, Android, Tizen, Sailfish and Ubuntu. Microsofts Windows phone, Windows RT and Windows 10 are used on a smaller number of tablets. On systems running the X Window System, desktop environments are more dynamic. All these individual modules can be exchanged and independently configured to suit users, not all of the program code that is part of a desktop environment has effects which are directly visible to the user. Some of it may be low-level code, KDE, for example, provides so-called KIO slaves which give the user access to a wide range of virtual devices
7.
Microsoft Windows
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Microsoft Windows is a metafamily of graphical operating systems developed, marketed, and sold by Microsoft. It consists of families of operating systems, each of which cater to a certain sector of the computing industry with the OS typically associated with IBM PC compatible architecture. Active Windows families include Windows NT, Windows Embedded and Windows Phone, defunct Windows families include Windows 9x, Windows 10 Mobile is an active product, unrelated to the defunct family Windows Mobile. Microsoft introduced an operating environment named Windows on November 20,1985, Microsoft Windows came to dominate the worlds personal computer market with over 90% market share, overtaking Mac OS, which had been introduced in 1984. Apple came to see Windows as an encroachment on their innovation in GUI development as implemented on products such as the Lisa. On PCs, Windows is still the most popular operating system, however, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android, because of the massive growth in sales of Android smartphones. In 2014, the number of Windows devices sold was less than 25% that of Android devices sold and this comparison however may not be fully relevant, as the two operating systems traditionally target different platforms. As of September 2016, the most recent version of Windows for PCs, tablets, smartphones, the most recent versions for server computers is Windows Server 2016. A specialized version of Windows runs on the Xbox One game console, Microsoft, the developer of Windows, has registered several trademarks each of which denote a family of Windows operating systems that target a specific sector of the computing industry. It now consists of three operating system subfamilies that are released almost at the time and share the same kernel. Windows, The operating system for personal computers, tablets. The latest version is Windows 10, the main competitor of this family is macOS by Apple Inc. for personal computers and Android for mobile devices. Windows Server, The operating system for server computers, the latest version is Windows Server 2016. Unlike its clients sibling, it has adopted a strong naming scheme, the main competitor of this family is Linux. Windows PE, A lightweight version of its Windows sibling meant to operate as an operating system, used for installing Windows on bare-metal computers. The latest version is Windows PE10.0.10586.0, Windows Embedded, Initially, Microsoft developed Windows CE as a general-purpose operating system for every device that was too resource-limited to be called a full-fledged computer. The following Windows families are no longer being developed, Windows 9x, Microsoft now caters to the consumers market with Windows NT. Windows Mobile, The predecessor to Windows Phone, it was a mobile operating system
8.
Start menu
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The Start menu is a user interface element used in Microsoft Windows since Windows 95 and in some other operating systems. It provides a launching point for computer programs and performing other tasks. It has different names in different operating systems and window managers, such as Kickoff Application Launcher in KDE, Dash in GNOME and Unity, later enhancements via Windows Desktop Update included access to special folders like My Documents and Favorites. Windows XPs Start menu was expanded to encompass various My Documents folders, until Windows Vista, the Start menu was constantly expanded across the screen as the user navigated through its cascading sub-menus. In Microsoft Windows, the Start menu in some form appears in Windows 9x, Windows NT4.0 and all subsequent versions in the Windows NT family, as well as Windows CE, Windows Mobile and Windows Phone. The Start menu was first introduced in Windows 95 and Windows NT4.0 to overcome the shortcomings of Program Manager in previous operating systems. Program Manager consisted of a multiple document interface which allowed users to open separate program groups. It lacked the ability to nest groups within other groups, Windows 95 and Windows NT4.0 replaced Program Manager with desktop and Start menu. Items could also be added to the Start menu by dragging and dropping them. The menu also offered the ability to shut down and log off from their computer, although Windows XP and Windows Server 2003 introduced a new version of Start menu, they offered the ability to switch back to this version of Start menu. This version of the Start menu is available in Windows Vista. However, it is absent in Windows 7, Windows Server 2008 R2, the next major change in the Start menu since its inception came in Windows XP and Windows Server 2003. This column also includes shortcuts for Computer and Network, which have traditionally placed on Windows Desktop. The contents of this column can be customized, commonly used programs are automatically displayed in the left-hand menu. Users may opt to pin programs to this side of the Start menu so that they are always accessible, a sub-menu item at the bottom of this column grants access to all items of Start menu. When this menu item is selected, a scrolling list of start menu programs replaces the user/recent list, Windows Vista and its successors added minor changes to the menu. In Windows Vista, however, cascading menus were replaced by a window in the left pane of the Start menu. Whenever All Programs item is clicked, the contents of the left pane slide off the edge of the Start menu
9.
Unix
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Among these is Apples macOS, which is the Unix version with the largest installed base as of 2014. Many Unix-like operating systems have arisen over the years, of which Linux is the most popular, Unix was originally meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmer users. The system grew larger as the system started spreading in academic circles, as users added their own tools to the system. Unix was designed to be portable, multi-tasking and multi-user in a time-sharing configuration and these concepts are collectively known as the Unix philosophy. By the early 1980s users began seeing Unix as a universal operating system. Under Unix, the system consists of many utilities along with the master control program. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space, the microkernel concept was introduced in an effort to reverse the trend towards larger kernels and return to a system in which most tasks were completed by smaller utilities. In an era when a standard computer consisted of a disk for storage and a data terminal for input and output. However, modern systems include networking and other new devices, as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, and semaphores. In microkernel implementations, functions such as network protocols could be moved out of the kernel, Multics introduced many innovations, but had many problems. Frustrated by the size and complexity of Multics but not by the aims and their last researchers to leave Multics, Ken Thompson, Dennis Ritchie, M. D. McIlroy, and J. F. Ossanna, decided to redo the work on a much smaller scale. The name Unics, a pun on Multics, was suggested for the project in 1970. Peter H. Salus credits Peter Neumann with the pun, while Brian Kernighan claims the coining for himself, in 1972, Unix was rewritten in the C programming language. Bell Labs produced several versions of Unix that are referred to as Research Unix. In 1975, the first source license for UNIX was sold to faculty at the University of Illinois Department of Computer Science, UIUC graduate student Greg Chesson was instrumental in negotiating the terms of this license. During the late 1970s and early 1980s, the influence of Unix in academic circles led to adoption of Unix by commercial startups, including Sequent, HP-UX, Solaris, AIX. In the late 1980s, AT&T Unix System Laboratories and Sun Microsystems developed System V Release 4, in the 1990s, Unix-like systems grew in popularity as Linux and BSD distributions were developed through collaboration by a worldwide network of programmers
10.
Microsoft
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Its best known software products are the Microsoft Windows line of operating systems, Microsoft Office office suite, and Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface tablet lineup, as of 2016, it was the worlds largest software maker by revenue, and one of the worlds most valuable companies. Microsoft was founded by Paul Allen and Bill Gates on April 4,1975, to develop and it rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Microsoft Windows. The companys 1986 initial public offering, and subsequent rise in its share price, since the 1990s, it has increasingly diversified from the operating system market and has made a number of corporate acquisitions. In May 2011, Microsoft acquired Skype Technologies for $8.5 billion, in June 2012, Microsoft entered the personal computer production market for the first time, with the launch of the Microsoft Surface, a line of tablet computers. The word Microsoft is a portmanteau of microcomputer and software, Paul Allen and Bill Gates, childhood friends with a passion for computer programming, sought to make a successful business utilizing their shared skills. In 1972 they founded their first company, named Traf-O-Data, which offered a computer that tracked and analyzed automobile traffic data. Allen went on to pursue a degree in science at Washington State University. The January 1975 issue of Popular Electronics featured Micro Instrumentation and Telemetry Systemss Altair 8800 microcomputer, Allen suggested that they could program a BASIC interpreter for the device, after a call from Gates claiming to have a working interpreter, MITS requested a demonstration. Since they didnt actually have one, Allen worked on a simulator for the Altair while Gates developed the interpreter and they officially established Microsoft on April 4,1975, with Gates as the CEO. Allen came up with the name of Micro-Soft, as recounted in a 1995 Fortune magazine article. In August 1977 the company formed an agreement with ASCII Magazine in Japan, resulting in its first international office, the company moved to a new home in Bellevue, Washington in January 1979. Microsoft entered the OS business in 1980 with its own version of Unix, however, it was MS-DOS that solidified the companys dominance. For this deal, Microsoft purchased a CP/M clone called 86-DOS from Seattle Computer Products, branding it as MS-DOS, following the release of the IBM PC in August 1981, Microsoft retained ownership of MS-DOS. Since IBM copyrighted the IBM PC BIOS, other companies had to engineer it in order for non-IBM hardware to run as IBM PC compatibles. Due to various factors, such as MS-DOSs available software selection, the company expanded into new markets with the release of the Microsoft Mouse in 1983, as well as with a publishing division named Microsoft Press. Paul Allen resigned from Microsoft in 1983 after developing Hodgkins disease, while jointly developing a new OS with IBM in 1984, OS/2, Microsoft released Microsoft Windows, a graphical extension for MS-DOS, on November 20,1985. Once Microsoft informed IBM of NT, the OS/2 partnership deteriorated, in 1990, Microsoft introduced its office suite, Microsoft Office
11.
Windows 95
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Windows 95 is a consumer-oriented operating system developed by Microsoft. It was released on August 24,1995, and was a significant improvement over the companys previous DOS-based Windows products, Windows 95 merged Microsofts formerly separate MS-DOS and Windows products. It featured significant improvements over its predecessor, Windows 3.1, most notably in the user interface. It was also suggested that Windows 95 had an effect of driving other major out of business. Three years after its introduction, Windows 95 was succeeded by Windows 98, Microsoft ended support for Windows 95 on December 31,2001. The initial design and planning of Windows 95 can be traced back to around March 1992, at this time, Windows for Workgroups 3.11 and Windows NT3.1 were still in development and Microsofts plan for the future was focused on Cairo. Cairo would be Microsofts next-generation operating system based on Windows NT and featuring a new interface and an object-based file system. However, Cairo would partially ship in July 1996 in the form of Windows NT4.0, but without the object-based file system, simultaneously with Windows 3. 1s release, IBM started shipping OS/22.0. Microsoft realized they were in need of a version of Windows that could support 32-bit applications and preemptive multitasking. So the development of Windows Chicago was started and, as it was planned for a late 1993 release, became known as Windows 93. Initially, the decision was not to include a new user interface, as this was planned for Cairo, and only focus on making installation, configuration. Windows 93 would ship together with MS-DOS7.0, offering an integrated experience to the user. The first version of Chicagos feature specification was finished on September 30,1992, cougar was to become Chicagos kernel. Prior to Windows 95s official release, users in the United States had an opportunity to preview it in the Windows 95 Preview Program. For US$19.95, users would receive several 3. 5-inch floppy disks that would be used to install Windows 95 either as an upgrade from Windows 3. 1x or as a fresh installation. Participants were also given a preview of The Microsoft Network. The preview versions expired in November 1995, after which the user would have to purchase their own copy of the version of Windows 95. Windows 95 was designed to be compatible with existing MS-DOS and 16-bit Windows programs and device drivers, while offering a more stable
12.
Filename
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A filename is a name used to uniquely identify a computer file stored in a file system. Different file systems impose different restrictions on filename lengths and the characters within filenames. Discussions of filenames are complicated by a lack of standardisation of the term, sometimes filename is used to mean the entire name, such as the Windows name c, \directory\myfile. txt. Sometimes, it will be used to refer to the components, sometimes, it is a reference that excludes an extension, so the filename would be just myfile. Such ambiguity is widespread and this article does not attempt to define any one meaning, some systems will adopt their own standardised nomenclature like path name, but these too are not standardised across systems. Around 1962, the Compatible Time-Sharing System introduced the concept of a file, around this same time appeared the dot as a filename extension separator, and the limit to three letter extensions might have come from RAD50 16-bit limits. Traditionally, filenames allowed only alphanumeric characters, but as time progressed and this led to compatibility problems when moving files from one file system to another. Around 1995, VFAT, an extension to the FAT filesystem, was introduced in Windows 95 and it allowed mixed-case Unicode long filenames, in addition to classic 8.3 names. In 1985, RFC959 officially defined a pathname to be the string that must be entered into a file system by a user in order to identify a file. One issue was migration to Unicode, for this purpose, several software companies provided software for migrating filenames to the new Unicode encoding. Microsoft provided migration transparent for the user throughout the vfat technology Apple provided File Name Encoding Repair Utility v1.0, Mac OS X10.3 marked Apples adoption of Unicode 3.2 character decomposition, superseding the Unicode 2.1 decomposition used previously. This change caused problems for writing software for Mac OS X. An absolute reference includes all directory levels, in some systems, a filename reference that does not include the complete directory path defaults to the current working directory. One advantage of using a reference in program configuration files or scripts is that different instances of the script or program can use different files. This makes an absolute or relative path composed of a sequence of filenames, Unix-like file systems allow a file to have more than one name, in traditional Unix-style file systems, the names are hard links to the files inode or equivalent. Windows supports hard links on NTFS file systems, and provides the command fsutil in Windows XP, hard links are different from Windows shortcuts, classic Mac OS/macOS aliases, or symbolic links. The introduction of LFNs with VFAT allowed filename aliases, with a maximum of eight plus three characters was a filename alias of long file name. As a way to conform to 8.3 limitations for older programs and this property was used by the move command algorithm that first creates a second filename and then only removes the first filename
13.
File Explorer
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File Explorer, previously known as Windows Explorer, is a file manager application that is included with releases of the Microsoft Windows operating system from Windows 95 onwards. It provides a user interface for accessing the file systems. It is also the component of the system that presents many user interface items on the monitor such as the taskbar. Controlling the computer is possible without Windows Explorer running, Windows Explorer was first included with Windows 95 as a replacement for File Manager, which came with all versions of Windows 3. x operating systems. Explorer could be accessed by double-clicking the new My Computer desktop icon, there is also a shortcut key combination, Windows key + E. Collectively, these features are known as the Windows shell. After a user logs in, the process is created by userinit process. Userinit performs some initialization of the environment and then looks in the registry at the Shell value and creates a process to run the system-defined shell – by default. This is why Explorer. exe is shown by various process explorers with no parent – its parent has exited, in 1995, Microsoft first released test versions of a shell refresh, named the Shell Technology Preview, and often referred to informally as NewShell. The update was designed to replace the Windows 3. x Program Manager/File Manager based shell with Windows Explorer, the release provided capabilities quite similar to that of the Windows Chicago shell during its late beta phases, however was intended to be nothing more than a test release. There were two releases of the Shell Technology Preview, made available to MSDN and CompuServe users,26 May 1995 and 8 August 1995. Both held Windows Explorer builds of 3.51.1053.1, the Shell Technology Preview program never saw a final release under NT3.51. The entire program was moved across to the Cairo development group who finally integrated the new design into the NT code with the release of NT4.0 in July 1996. At the time these changes raised antitrust concerns about the incorporation of what was seen as an application feature, an address bar was also added to Windows Explorer, which a user could type in directory paths directly, and be taken to that folder. It also operated as a URL bar for Internet addresses, web pages would open in the portion of the window. Another feature that was based on Internet Explorer technology was customized folders, such folders contained a hidden web page that controlled the way the Windows Explorer displayed the contents of the folder. This feature proved to have security due to its reliance on ActiveX objects and scripting. Other new features, The ability to add toolbars to the task bar. Active Desktop, which made it possible to turn the desktop background itself into a web page, single-click activation of icons in Windows Explorer, adhering to a web page paradigm
14.
Windows 9x
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This includes all versions of Windows 95 and Windows 98. Windows 9x is predominantly known for its use in desktops, in 1998, Windows made up 82% of operating system market share. Internal release versions for versions of Windows 9x are 4. x, previous MS-DOS based versions of Windows used version numbers of 3.2 or lower. Windows NT, which was aimed at professional users such as networks and businesses, used a similar, the final version of Windows 9x was Windows ME, released in September 2000 with an internal version number of 4.9. All future versions of Windows, starting with Windows XP, would be based on the Windows NT codebase, the first independent version of Microsoft Windows, version 1.0, released on 20 November 1985, achieved little popularity. It was originally going to be called Interface Manager but Rowland Hanson, Windows 1.0 was not a complete operating system, but rather an operating environment that extended MS-DOS, and shared the latters inherent flaws and problems. The second release of Microsoft Windows, version 2.0, came out on 9 December 1987, and used the memory model. In such a configuration, it could run under another multitasking system like DESQview, Microsoft Windows scored a significant success with Windows 3.0, released in 1990. Microsoft developed Windows 3.1, which included minor improvements to Windows 3.0. It also excluded support for Real mode, and only ran on an 80286 or better processor. Later Microsoft also released Windows 3.11, a touch-up to Windows 3.1 which included all of the patches and updates that followed the release of Windows 3.1 in 1992, meanwhile, Microsoft continued to develop Windows NT. The main architect of the system was Dave Cutler, one of the architects of VMS at Digital Equipment Corporation. Microsoft hired him in August 1988 to create a successor to OS/2, Microsoft announced at the conference its intentions to develop a successor to both Windows NT and Windows 3. 1s replacement, which would unify the two into one operating system. In hindsight, Cairo was a more difficult project than Microsoft had anticipated and, as a result, NT. After Windows 3.11, Microsoft began to develop a new consumer oriented version of the operating system code-named Chicago, Chicago was designed to have support for 32-bit preemptive multitasking like OS/2 and Windows NT, although a 16-bit kernel would remain for the sake of backward compatibility. The Win32 API first introduced with Windows NT was adopted as the standard 32-bit programming interface, a new GUI was not originally planned as part of the release, although elements of the Cairo user interface were borrowed and added as other aspects of the release slipped. Microsoft did not change all of the Windows code to 32-bit, parts of it remained 16-bit for reasons of compatibility, performance and these factors immediately began to impact the operating systems efficiency and stability. Microsoft marketing adopted Windows 95 as the name for Chicago when it was released on August 24,1995
15.
Windows NT
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Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It is a processor-independent, multiprocessing, multi-user operating system, the first version of Windows NT was Windows NT3.1 and was produced for workstations and server computers. It was intended to complement consumer versions of Windows that were based on MS-DOS, gradually, the Windows NT family was expanded into Microsofts general-purpose operating system product line for all personal computers, deprecating the Windows 9x family. NT was formerly expanded to New Technology but no longer carries any specific meaning, starting with Windows 2000, NT was removed from the product name and is only included in the product version string. NT was the first purely 32-bit version of Windows, whereas its consumer-oriented counterparts, Windows 3. 1x and it is a multi-architecture operating system. Initially, it supported several CPU architectures, including IA-32, MIPS, DEC Alpha, PowerPC, the latest versions support x86 and ARM. This lineage is made clear in Cutlers foreword to Inside Windows NT by Helen Custer and it has been suggested that Dave Cutler intended the initialism WNT as a play on VMS, incrementing each letter by one. However, the project was intended as a follow-on to OS/2 and was referred to as NT OS/2 before receiving the Windows brand. One of the original NT developers, Mark Lucovsky, states that the name was taken from the original target processor—the Intel i860, the letters were dropped from the names of releases from Windows 2000 onwards, though Microsoft described that product as being Built on NT Technology. A main design goal of NT was hardware and software portability, the idea was to have a common code base with a custom Hardware Abstraction Layer for each platform. However, support for MIPS, Alpha, and PowerPC was later dropped in Windows 2000, broad software compatibility was achieved with support for several API personalities, including Windows API, POSIX, and OS/2 APIs – the latter two were phased out starting with Windows XP. Partial MS-DOS compatibility was achieved via an integrated DOS Virtual Machine – although this feature is being phased out in the x86-64 architecture, NT supported per-object access control lists allowing a rich set of security permissions to be applied to systems and services. NT supported Windows network protocols, inheriting the previous OS/2 LAN Manager networking, Windows NT3.1 was the first version of Windows to use 32-bit flat virtual memory addressing on 32-bit processors. Its companion product, Windows 3.1, used segmented addressing, notably, in Windows NT3. x, several I/O driver subsystems, such as video and printing, were user-mode subsystems. In Windows NT4, the video, server, and printer spooler subsystems were moved into kernel mode, NTFS, a journaled, secure file system, was created for NT. Windows NT also allows for other file systems, starting with versions 3.1. Windows NT introduced its own model, the Windows NT driver model. With Windows 2000, the Windows NT driver model was enhanced to become the Windows Driver Model, which was first introduced with Windows 98, but was based on the NT driver model
16.
NTFS
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NTFS is a proprietary file system developed by Microsoft. Starting with Windows NT3.1, it is the file system of Windows NT family. Additional extensions are an elaborate security system based on Access control lists. MacOS kernels also have a limited ability to read NTFS. Linux and BSD kernels have a free and open-source driver for the NTFS filesystem with both read and write functionality, in the mid-1980s, Microsoft and IBM formed a joint project to create the next generation of graphical operating system, the result was OS/2 and HPFS. Because Microsoft disagreed with IBM on many important issues they eventually separated, OS/2 remained an IBM project and Microsoft worked to develop Windows NT, the HPFS file system for OS/2 contained several important new features. When Microsoft created their new operating system, they borrowed many of these concepts for NTFS, NTFS developers include, Tom Miller, Gary Kimura, Brian Andrew and David Goebel. Probably as a result of common ancestry, HPFS and NTFS use the same disk partition identification type code. Using the same Partition ID Record Number is highly unusual, since there were dozens of unused code numbers available, for example, FAT has more than nine. Algorithms identifying the system in a partition type 07 must perform additional checks to distinguish between HPFS and NTFS. Microsoft has released five versions of NTFS, v1.0, v1.0 is incompatible with v1.1 and newer, Volumes written by Windows NT3. 5x cannot be read by Windows NT3.1 until an update is installed. V1.1, Released with Windows NT3.51 in 1995, supports compressed files, named streams and access control lists v1.2, Released with Windows NT4.0 in 1996. Commonly called NTFS4.0 after the OS release, supports disk quotas, Encrypting File System, sparse files, reparse points, update sequence number journaling, the $Extend folder and its files. Reorganized security descriptors so that multiple files using the same security setting can share the same descriptor, commonly called NTFS5.0 after the OS release. V3.1, Released with Windows XP in Autumn,2001, expanded the Master File Table entries with redundant MFT record number. Commonly called NTFS5.1 after the OS release The NTFS. sys version number is based on the system version. Although subsequent versions of Windows added new file system-related features, they did not change NTFS itself, for example, Windows Vista implemented NTFS symbolic links, Transactional NTFS, partition shrinking, and self-healing. NTFS symbolic links are a new feature in the file system, NTFS is optimized for 4 kB clusters, but supports a maximum cluster size of 64 kB
17.
Windows Installer
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Windows Installer is a software component and application programming interface of Microsoft Windows used for the installation, maintenance, and removal of software. Windows Installer contains significant changes from its predecessor, Setup API, new features include a GUI framework and automatic generation of the uninstallation sequence. Windows Installer is positioned as an alternative to stand-alone executable installer frameworks such as versions of InstallShield. Important features such as rollback and versioning depend on a consistent internal database for reliable operation, furthermore, Windows Installer facilitates the principle of least privilege by performing software installations by proxy for unprivileged users. A package describes the installation of one or more products and is universally identified by a GUID. A product is made up of components, grouped into features, Windows Installer does not handle dependencies between products. A single, installed, working program is a product, a product is identified by a unique GUID providing an authoritative identity throughout the world. The GUID, in combination with the number, allows for release management of the products files. A package includes the package logic and other metadata that relates to how the package executes when running, for example, changing an EXE file in the product may require the ProductCode or ProductVersion to be changed for the release management. However, merely changing or adding a condition would still require the PackageCode to change for release management of the MSI file itself. A feature is a group of components. A feature may contain any number of components and other sub-features, smaller packages can consist of a single feature. More complex installers may display a custom setup dialog box, from which the user can select which features to install or remove, the package author defines the product features. A word processor, for example, might place the programs core file into one feature, a component is the basic unit of a product. Each component is treated by Windows Installer as a unit, the installer cannot install just part of a component. Components can contain files, folders, COM components, registry keys. The user does not directly interact with components, components are identified globally by GUIDs, thus the same component can be shared among several features of the same package or multiple packages, ideally through the use of Merge Modules. A key path is a file, registry key, or ODBC data source that the package author specifies as critical for a given component
18.
Windows 2000
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Windows 2000 is an operating system for use on both client and server computers. It was produced by Microsoft and released to manufacturing on December 15,1999 and it is the successor to Windows NT4.0, and is the last version of Microsoft Windows to display the Windows NT designation. It is succeeded by Windows XP and Windows Server 2003, during development, Windows 2000 was known as Windows NT5.0. Four editions of Windows 2000 were released, Professional, Server, Advanced Server, and Datacenter Server, Windows 2000 introduces NTFS3.0, Encrypting File System, as well as basic and dynamic disk storage. Support for people with disabilities was improved over Windows NT4.0 with a number of new assistive technologies, the Windows 2000 Server family has additional features including the ability to provide Active Directory services. Windows 2000 can be installed either a manual or unattended installation. Microsoft marketed Windows 2000 as the most secure Windows version ever at the time, however, it became the target of a number of high-profile virus attacks such as Code Red and Nimda. For ten years after its release, it continued to receive patches for security vulnerabilities nearly every month until reaching the end of its lifecycle on July 13,2010. Windows 2000 is a continuation of the Microsoft Windows NT family of operating systems, the original name for the operating system was Windows NT5.0 and its Beta 1 was released in September 1997, followed by Beta 2 in August 1998. On October 27,1998, Microsoft announced that the name of the version of the operating system would be Windows 2000. Windows 2000 Beta 3 was released in January 1999, NT5.0 Beta 1 was similar to NT4.0, including a very similar themed logo. NT5.0 Beta 2 introduced a new boot screen. The new login prompt from the version made its first appearance in Beta 3 build 1946. The new, updated icons first appeared in Beta 3 build 1976, the Windows 2000 boot screen in the final version first appeared in Beta 3 build 1994. Windows 2000 did not have a codename because, according to Dave Thompson of Windows NT team, Windows 2000 Service Pack 1 was codenamed Asteroid and Windows 2000 64-bit was codenamed Janus. During development, there was a build for the Alpha which was abandoned some time after RC1 after Compaq announced they had dropped support for Windows NT on Alpha. From here, Microsoft issued three release candidates between July and November 1999, and finally released the system to partners on December 12,1999. The public could buy the version of Windows 2000 on February 17,2000
19.
File system
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In computing, a file system or filesystem is used to control how data is stored and retrieved. Without a file system, information placed in a storage medium would be one large body of data with no way to tell where one piece of information stops, by separating the data into pieces and giving each piece a name, the information is easily isolated and identified. Taking its name from the way paper-based information systems are named, the structure and logic rules used to manage the groups of information and their names is called a file system. There are many different kinds of file systems, each one has different structure and logic, properties of speed, flexibility, security, size and more. Some file systems have been designed to be used for specific applications, for example, the ISO9660 file system is designed specifically for optical discs. File systems can be used on different types of storage devices that use different kinds of media. The most common device in use today is a hard disk drive. Other kinds of media that are used include flash memory, magnetic tapes, in some cases, such as with tmpfs, the computers main memory is used to create a temporary file system for short-term use. Some file systems are used on local storage devices, others provide file access via a network protocol. Some file systems are virtual, meaning that the files are computed on request or are merely a mapping into a different file system used as a backing store. The file system access to both the content of files and the metadata about those files. It is responsible for arranging storage space, reliability, efficiency, before the advent of computers the term file system was used to describe a method of storing and retrieving paper documents. By 1961 the term was being applied to computerized filing alongside the original meaning, by 1964 it was in general use. A file system consists of two or three layers, sometimes the layers are explicitly separated, and sometimes the functions are combined. The logical file system is responsible for interaction with the user application and it provides the application program interface for file operations — OPEN, CLOSE, READ, etc. and passes the requested operation to the layer below it for processing. The logical file system manage open file table entries and per-process file descriptors and this layer provides file access, directory operations, security and protection. The second optional layer is the file system. This interface allows support for multiple concurrent instances of physical file systems, the third layer is the physical file system
20.
Windows 7
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Windows 7 is a personal computer operating system developed by Microsoft. It is a part of the Windows NT family of operating systems, Windows 7 was released to manufacturing on July 22,2009, and became generally available on October 22,2009, less than three years after the release of its predecessor, Windows Vista. Windows 7s server counterpart, Windows Server 2008 R2, was released at the same time, Windows 7 continued improvements on Windows Aero with the addition of a redesigned taskbar that allows applications to be pinned to it, and new window management features. Other new features were added to the system, including libraries, the new file sharing system HomeGroup. A new Action Center interface was added to provide an overview of system security and maintenance information. Windows 7 also shipped with updated versions of several applications, including Internet Explorer 8, Windows Media Player. Windows 7 was a success for Microsoft, even prior to its official release. Originally, a version of Windows codenamed Blackcomb was planned as the successor to Windows XP, major features were planned for Blackcomb, including an emphasis on searching and querying data and an advanced storage system named WinFS to enable such scenarios. However, an interim, minor release, codenamed Longhorn, was announced for 2003, by the middle of 2003, however, Longhorn had acquired some of the features originally intended for Blackcomb. Development of Longhorn was also restarted, and thus delayed, in August 2004, a number of features were cut from Longhorn. Blackcomb was renamed Vienna in early 2006, as such, adoption of Vista in comparison to XP remained somewhat low. In July 2007, six months following the release of Vista, it was reported that the next version of Windows would then be codenamed Windows 7. Bill Gates, in an interview with Newsweek, suggested that Windows 7 would be more user-centric, Gates later said that Windows 7 would also focus on performance improvements. Senior Vice President Bill Veghte stated that Windows Vista users migrating to Windows 7 would not find the kind of device compatibility issues they encountered migrating from Windows XP, an estimated 1,000 developers worked on Windows 7. These were broadly divided into core operating system and Windows client experience, in October 2008, it was announced that Windows 7 would also be the official name of the operating system. The first external release to select Microsoft partners came in January 2008 with Milestone 1, at PDC2008, Microsoft demonstrated Windows 7 with its reworked taskbar. On December 27,2008, the Windows 7 Beta was leaked onto the Internet via BitTorrent. According to a performance test by ZDNet, Windows 7 Beta beat both Windows XP and Vista in several key areas, including boot and shutdown time and working with files, such as loading documents
21.
GNOME
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GNOME is a desktop environment composed of free and open-source software that runs on Linux and most BSD derivatives. GNOME was originally an acronym for GNU Network Object Model Environment, GNOME is developed by The GNOME Project, which is composed of both volunteers and paid contributors, the largest corporate contributor being Red Hat. GNOME is part of the GNU Project, since GNOME2, productivity has been a key focus for GNOME. To this end, the GNOME Human Interface Guidelines were created, all GNOME programs share a coherent style of graphical user interface but are not limited to the employment of the same GUI widgets. Rather, the design of the GNOME GUI is guided by concepts described in the GNOME HIG, following the HIG, developers can create high-quality, consistent, and usable GUI programs, as it addresses everything from GUI design to recommended pixel-based layout of widgets. During the GNOME2 rewrite, many settings deemed of value to the majority of users were removed. Or even configurable to be the union of all applications that anyones ever seen on any historical platform and it turns out that preferences have a cost. Of course, some also have important benefits – and can be crucial interface features. But each one has a price, and you have to consider its value. Many users and developers dont understand this, and end up with a lot of cost, GNOME aims to make and keep the desktop environment physically and cognitively ergonomic for people with disabilities. The GNOME HIG tries to take this account as far as possible. Particular utilities are registered with ATK using Assistive Technology Service Provider Interface, several assistive technology providers, including Orca screen reader and Dasher input method, were developed specifically for use with GNOME. GNOME Shell is the user interface of the GNOME desktop environment. It features a top bar holding an Activities button, a menu, a clock. The status menu holds various system status indicators, shortcuts to system settings, and session actions including logging out, switching users, locking the screen, clicking on the Activities button, moving the mouse to the top-left hot corner or pressing the Super key brings up the Overview. The Overview gives users an overview of current activities and provides a way to switch between windows and workspaces and to launch applications, the Dash on the left houses shortcuts to favorite applications and open windows and an application picker button to show a list of all installed applications. A search bar appears at the top and a workspace list for switching between workspaces is on the right, notifications appear from the bottom of the screen. Beginning with GNOME3.8, GNOME provides a Classic Mode for those who prefer a traditional desktop experience, GNOME3.24 will extend Wayland compatibility to NVidia drivers
22.
KDE
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KDE is an international free software community that develops Free and Libre software. Well-known products include the Plasma Desktop, KDE Frameworks and a range of applications designed to run on modern Unix-like. It further provides tools and documentation for developers that enables them to write software and this supporting role makes KDE a central development hub and home for many popular applications and projects like Calligra Suite, Krita or digiKam. The Plasma Desktop, being one of the most recognized projects of KDE, is the desktop environment on many Linux distributions, such as openSUSE, Mageia, Chakra, Kubuntu. It was also the default desktop environment on PC-BSD, but was replaced with Lumina. The work of the KDE community can be measured in the following figures, more than 1800 contributors participate in developing KDE software. About 20 new developers contribute their first code each month, KDE Software consists of over 6 million lines of code. KDE Software is translated in over 108 languages, KDE Software is available on more than 114 official FTP mirrors in over 34 countries. A read-only mirror of all repositories can be found on Github, K Desktop Environment was founded in 1996 by Matthias Ettrich, who was then a student at the Eberhard Karls University of Tübingen. At the time, he was troubled by certain aspects of the Unix desktop, among his concerns was that none of the applications looked, felt, or worked alike. He proposed the creation of not merely a set of applications but a desktop environment in which users could expect things to look, feel, and work consistently. He also wanted to make this easy to use, one of his complaints about desktop applications of the time was that it is too complicated for end user. His initial Usenet post spurred a lot of interest, and the KDE project was born, the name KDE was intended as a wordplay on the existing Common Desktop Environment, available for Unix systems. CDE is an X11-based user environment jointly developed by HP, IBM and it was supposed to be an intuitively easy-to-use desktop computer environment. The K was originally suggested to stand for Kool, but it was decided that the K should stand for nothing in particular. Therefore, the KDE initialism expanded to K Desktop Environment before it was dropped altogether in favor of KDE = Community due to the rebranding effort. The rebranding focused on de-emphasizing the desktop environment as just another product, what would have been previously known as KDE4 was split into three products, Plasma Workspaces, KDE Applications, and KDE Platform – bundled as KDE Software Compilation 4. As of today the name KDE no longer stands for K Desktop Environment, the financial and legal matters of KDE are handled by KDE e. V
23.
Freedesktop.org
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Freedesktop. org is a project to work on interoperability and shared base technology for free software desktop environments for the X Window System on Linux and other Unix-like operating systems. It was founded by Havoc Pennington from Red Hat in March 2000, the project is hosted by Software in the Public Interest, the non-profit organization created by the Debian Project. There are many development frameworks for X, and this is unlikely to change, the organization seeks to ensure that differences in development frameworks are not user-visible. Widely used open-source X desktop projects—such as GNOME, KDE, in 2006, the project released Portland 1.0, a set of common interfaces for desktop environments. Freedesktop. org was formerly known as the X Desktop Group, freedesktop. org provides hosting for a number of relevant projects. These include, Software related to windowing systems and graphics in general Cairo, direct Rendering Infrastructure, Linux API to access the graphics hardware, used by X11, Wayland compositors, Mesa 3D, etc. Glamor, 2D graphics common driver for X server, it supports a variety of graphics chipsets which have supports for OpenGL/EGL/GBM APIs Mesa 3D, pixman, is a low-level software library for pixel manipulation, providing features such as image compositing and trapezoid rasterization. Important users of pixman are the cairo graphics library and the X. Org Server Poppler, gTK-Qt engine, a GTK+2 engine which uses Qt to draw the graphical control elements, providing the same look and feel of KDE applications to GTK+2 applications. HAL is a consistent cross-operating system layer, it has been deprecated and replaced by udev. Org input driver, systemd is a comprehensive init framework to start and manage services and sessions meant to replace older init models. Xft, anti-aliased fonts using the FreeType library, rather than the old X core fonts, also, Avahi started as a fd. o project but has now moved elsewhere. The project aims to catch interoperability issues much earlier in the process and it is not for legislating formal standards. X. Org Foundation Comparison of open source software hosting facilities Linux on the desktop Notes The Big freedesktop. org Interview Official website
24.
Window manager
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A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to provide a desktop environment. Few window managers are designed with a distinction between the windowing system and the window manager. Every graphical user interface based on a windows metaphor has some form of window management, in practice, the elements of this functionality vary greatly. Elements usually associated with window managers allow the user to open, close, minimize, maximize, move, resize, many window managers also come with various utilities and features, e. g. docks, task bars, program launchers, desktop icons, and wallpaper. On systems using the X window system, there is a distinction between the window manager and the windowing system. Strictly speaking, an X window manager does not directly interact with hardware, mice. Users of the X Window System have the ability to use many different window managers – Metacity, used in GNOME2, and KWin, used in KDE Plasma Workspaces. Since many window managers are modular, people can use others, such as Compiz, sawfish and awesome on the other hand are extensible window managers offering exacting window control. Components of different window managers can even be mixed and matched, for example, Window managers under the X window system adopt applications from the root window and re-parent them to window decorations. Re-parenting can also be used to add the contents of one window to another, for example, a flash player application can be re-parented to a browser window, and can appear to the user as supposedly being part of that program. Re-parenting window managers can therefore arrange one or more programs into the same window, Microsoft Windows has provided an integrated stacking window manager since Windows 2.0, Windows Vista introduced the compositing Desktop Window Manager as an optional hardware-accelerated alternative. Since Windows 8, the Desktop Window Manager can no longer be disabled, the Windows window manager can also act as an X window manager through Cygwin/X in multiwindow mode. Note that Microsoft and X Window System use different terms to describe similar concepts, for example, there is no specific word for window manager functionality in Windows. Window managers are often divided into three or more classes, which describe how windows are drawn and updated, Compositing window managers let all windows be created and drawn separately and then put together and displayed in various 2D and 3D environments. The most advanced compositing window managers allow for a deal of variety in interface look and feel. All window managers that have overlapping windows and are not compositing window managers are stacking window managers, stacking window managers allow windows to overlap by drawing background windows first, which is referred to as painters algorithm. Changes sometimes require that all windows be re-stacked or repainted, which usually involves redrawing every window, tiling window managers paint all windows on-screen by placing them side by side or above and below each other, so that no window ever covers another
25.
Cwm (window manager)
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Cwm is a stacking window manager for the X Window System. While it is developed as a part of OpenBSDs base system. Development of cwm started from patches to evilwm by Marius Aamodt Eriksen, some of 9wm code was used for rewrite. The last release by the author came out in August 2005. In April 2007, the cwm was imported into OpenBSD source tree, by January 2008 substantial part of the original source code was rewritten. Currently cwm is distributed with OpenBSD since release 4.2, cwm is a stacking window manager oriented towards heavy keyboard usage, small footprint and ease of use. While it lacks explicit virtual desktops functionality, it can be emulated by using the window groups mechanism, cwm doesnt draw window decorations except for 1 pixel border around the windows. Cwm includes several menus, exec menu window menu ssh to menu exec wm menu All these menus are operated in search as you type manner, cwm allows raising, hiding switching and searching windows with no use of mouse, making it suitable to use as terminal emulator multiplexer. Furthermore, it allows manipulating pointing device with keyboard, the additional key bindings and configuration options can be specified in configuration file ~/. cwmrc. Cwm is generally positively received in software minimalist communities, though it often gets no explanation, several OpenBSD users prefer to use cwm under Linux, even if it requires modifying and supporting source code. Cwm is also praised for its flexibility, ability to interact in a non-disruptive way, comparison of X window managers cwm – OpenBSD General Commands Manual cwmrc – OpenBSD File Formats Manual Official website at the Wayback Machine cwm on GitHub – unofficial portable version of cwm
26.
Dwm
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Dwm is a dynamic, minimalist tiling window manager for the X Window System that has influenced the development of several other X window managers, including xmonad and awesome. It is externally similar to wmii, but internally much simpler, dwm is written purely in C for performance and security in addition to simplicity, and lacks any configuration interface besides editing the source code. One of the guidelines is that the source code will never exceed 2000 lines. Dwm supports multiple workspaces and, unlike ratpoison, allows moving and resizing windows with the mouse, older versions of dwm displayed their stdin in a status bar, along the edge of the screen. Recent versions instead display the root name, which can be set by independent processes. Dmenu is a keyboard-driven menu utility developed as part of the dwm project, when invoked, usually by a user-configured key combination, dmenu displays a horizontal menu of its stdin stream at the top edge of the screen. This is usually used to pipe in a list of names from the users $PATH. The user can start typing a program name, and dmenu will narrow the list to show only substring matches for what the user typed, the user can also use the arrow keys to navigate the menu. When a choice is made, dmenu sends the text to stdout. Command-line options can alter the font and colors of the menu, make the search case-insensitive, by default, only X Font Server fonts are supported although a patch exists to enable TrueType fonts using Xft. In addition to dwm, dmenu is often used with other window managers like xmonad, or Openbox, dwm has been an influential project, many other window managers are based on dwms source code or inspired by it. An extensive list of forks and patches can be found at the official site, below is a list of a few notable examples, awesome extends dwm with FreeType support, reconfigurability, Lua scripting support, theming, and more layout types. Echinus extends dwm with FreeType support, subset of EWMH, click-to-focus, reconfigurability, wmii is a tiling window manager from which dwm draws inspiration. Xmonad is a dwm rewrite in Haskell with additional features
27.
Metacity
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Metacity /məˈtæsɪti/ was the default window manager used by the GNOME2 desktop environment until it was replaced by Mutter in GNOME3. It is still used by GNOME Flashback, a session for GNOME3 that provides a user experience to the Gnome 2. x series sessions. A fork, Marco, is still being developed and maintained as part of the MATE desktop environment. The development of Metacity was started by Havoc Pennington and it was released under the GNU General Public License, before the introduction of Metacity in GNOME2.2, GNOME used Enlightenment and then Sawfish as its window manager. Metacity uses the GTK+ graphical widget toolkit to create its user interface components, originally, Metacity used GTK+2 however as of version 3.12.0 it has been ported to GTK+3. Metacitys focus is on simplicity and usability rather than novelties and its author has characterized it as a Boring window manager for the adult in you. Many window managers are like Marshmallow Froot Loops, Metacity is like Cheerios, people in favour of Metacity say that it is aimed at new computer users who do not need the abundant options and functionality of Sawfish or Enlightenment. Havoc Pennington wrote an essay explaining why he wrote Metacity and simplified the GNOME desktop, devils Pie and Brightside are among the packages that enable increased control over windows, however these applications cannot override Metacitys key bindings. Despite the incomplete state of Metacity theme development documentation, many themes have been written for Metacity, a huge number of such themes can be downloaded from GNOMEs art site, art. gnome. org. A popular theme engine is Clearlooks, which has been GNOMEs default since version 2.12, comparison of X window managers Metacity blog Metacity Download Site Metacity Themes Understanding Metacity Themes, Thomas Thurman
28.
Window Maker
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Window Maker is a free and open source window manager for the X Window System, allowing graphical applications to be run on Unix-like operating-systems. It is designed to emulate NeXTSTEPs GUI as an OpenStep-compatible environment, Window Maker is part of the GNU Project. Window Maker has a reputation for being fast, efficient and highly stable, Window Maker has been characterized as reproducing the elegant look and feel of the NeXTstep GUI and is noted as easy to configure and easy to use. A graphical tool called Wprefs is included and can be used to configure most aspects of the UI, menus and preferences can be changed without restarting. As with most window managers it supports themes and many are available, owing to its NeXTstep-like design, like the GUI of Apple Incs OS X, Window Maker has a dock, but Window Makers look and feel hews mostly to that of its NeXT forebear. Window Maker has window hints which allow seamless integration with the GNUstep, GNOME, KDE, Motif, significantly it has almost complete ICCCM compliance and internationalization support for at least 11 locales. Window Maker uses the lightweight WINGs widget set which was specifically for Window Maker as a way to skirt what its developers said would have been the overkill of using GNUstep. WINGs is common to other applications including a display manager called WINGs Display Manager. Window Maker dock and clip applets are compatible with those from AfterSteps wharf, the first release was in 1997. For a time it was included as a window manager in several Linux distributions and is also available in the FreeBSD and OpenBSD ports collection. Since the goal of the project has been to emulate the design of the defunct NeXTstep and OpenStep GUIs. In late 2007 the widely available, stable version was at 0.92 from July 2005 with subsequent maintenance updates having been made to some distribution packages. In late June 2008 a post on the website said active development would resume. We expect to once again provide the de-facto minimalist yet extremely functional window manager to the world, on 29 January 2012, Window Maker 0.95.1 was released, making it the first official release in almost seven years. This was followed by a number of releases, As of September 2015 the latest release was 0.95.7, a 1998 agreement between the developers of Window Maker and Windowmaker Software specified that Window Maker should never be used as a single word. Keyboard users can use F12 for the menu and F11 for a window menu. Window Maker can be configured by double-clicking the screwdriver icon on the dock, an icon depicting a computer monitor is used to launch a command-window and a paperclip icon is used to cycle between workspaces. Any icon in Window Maker, including icons, can be easily changed
29.
System 7
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System 7 is a single-user graphical user interface-based operating system for Macintosh computers and was part of the classic Mac OS line of operating systems. It was introduced on May 13,1991, by Apple Computer and it succeeded System 6, and was the main Macintosh operating system until it was succeeded by Mac OS8 in 1997. Features added with the System 7 release included virtual memory, personal file sharing, QuickTime, QuickDraw 3D, System 7 is often used generically to refer to all 7. x versions. With the release of version 7.6 in 1997, Apple officially renamed the operating system Mac OS, System 7 was developed for Macs that used the Motorola 680x0 line of processors, but was ported to the PowerPC after Apple adopted the new processor. The development of the Macintosh Systems up to System 6 followed a smooth progression with the addition of new features. Major additions were fairly limited, notably adding Color QuickDraw and MultiFinder in System 6, some perspective on the scope of the changes can be seen by examining the official system documentation, Inside Macintosh. This initially shipped in three volumes, adding another to describe the changes introduced with the Mac Plus, and another for the Mac II and these limited changes meant that the original Mac system remained largely as it was when initially introduced. That is, the machine was geared towards a single user, however, many of the assumptions of this model were no longer appropriate. Most notable among these was the model, the replacement of which had first been examined in 1986s Switcher. Running MultiFinder normally required larger amount of RAM and a hard drive, while additions had been relatively limited, so had fixes to some of the underlying oddities of the system architecture. If the system were able to support tasks, this one-off solution would no longer be needed - desk accessories could simply be small programs. Yet, as MultiFinder was still optional, such a step had not been taken, numerous examples of this sort of problem could be found throughout the system. Finally, the adoption of hard drives and local area networks led to any number of new features being requested from users and developers. By the late 1980s, the list of new upgrades and suggested changes to the model was considerable. In March 1988, shortly after the release of System 6, development of the ideas contained on the blue and pink cards was to proceed in parallel, and at first the two projects were known simply as blue and pink. Apple intended to have the team release an updated version of the existing Macintosh operating system in the 1990–1991 timeframe. As Blue was aimed at relatively simple upgrades, the feature list reads to some degree as a sort of System 6, a new Sound Manager API, version 2.0, replaced the older ad hoc APIs. The new APIs featured significantly improved hardware abstraction, as well as higher-quality playback, although technically not a new feature for System 7, Sound Manager 2.0 was the first widespread implementation of this technology to make it to most Mac users
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Mac OS 8
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Mac OS8 is an operating system that was released by Apple Computer on July 26,1997. It represented the largest overhaul of the classic Mac OS since the release of System 7 and it puts more emphasis on color than previous operating systems. Released over a series of updates, Mac OS8 was an effort to many of the technologies developed for Apples overly-ambitious operating system known as Copland. Coming as it did at a time in Apples history, many pirate groups refused to traffic in the new operating system. Mac OS8.0 brought about the most visible changes in the line-up, including the introduction of the Platinum interface, Mac OS8.1 introduced a new, more efficient file system known as HFS Plus. Mac OS8.5 was the first version of the Mac OS to require a PowerPC processor and it featured PowerPC native versions of QuickDraw and AppleScript, along with the Sherlock search utility. Its successor, Mac OS9, was released on October 23,1999, Apples next generation operating system, which it originally envisioned as System 8 was codenamed Copland. It was announced in March 1994 alongside the introduction of the first PowerPC Macs, Copland was to be followed by Gershwin, which promised protected memory spaces and full preemptive multitasking. The operating system was intended to be a complete re-write of the Mac OS, the Copland development was hampered by countless missed deadlines. The release date was first pushed back to the end of 1995, then to mid-96, late 96, with a dedicated team of 500 software engineers and an annual budget of $250 million, Apple executives began to grow impatient with the project continually falling behind schedule. These updates began with Mac OS7.6, released during WWDC, Mac OS8.0, released six months later, continued to integrate Copland technologies into the Mac OS. In August 1996, Apple Chief Technology Officer, Ellen Hancock, froze development of Copland and this ultimately led to Apples purchase of NeXT and the development of Mac OS X. Developed under the codename Tempo, Mac OS8.0 was released on July 26,1997, initially, the early beta releases of the product which were circulated to developers and Apple internal audiences, were branded as Mac OS7.7. Afterwards, the software was renamed to Mac OS8 before the final release. Major improvements in this included the Platinum theme, a Finder which was PowerPC native and multi-threaded. Other features introduced in Mac OS8.0 include the following, Customization of system fonts, Pop-up context menus Pop-up windows in the Finder. Multithreaded Finder — file copy operations run in a separate thread, desktop Pictures control panel, allowing photographs to be set as the desktop background. Simple Finder, an option which reduces Finder menus to basic operations, relocation of the Help menu from an icon at the right end of the menu bar to a standard textual menu positioned after the applications menus
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MacOS
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Within the market of desktop, laptop and home computers, and by web usage, it is the second most widely used desktop OS after Microsoft Windows. Launched in 2001 as Mac OS X, the series is the latest in the family of Macintosh operating systems, Mac OS X succeeded classic Mac OS, which was introduced in 1984, and the final release of which was Mac OS9 in 1999. An initial, early version of the system, Mac OS X Server 1.0, was released in 1999, the first desktop version, Mac OS X10.0, followed in March 2001. In 2012, Apple rebranded Mac OS X to OS X. Releases were code named after big cats from the release up until OS X10.8 Mountain Lion. Beginning in 2013 with OS X10.9 Mavericks, releases have been named after landmarks in California, in 2016, Apple rebranded OS X to macOS, adopting the nomenclature that it uses for their other operating systems, iOS, watchOS, and tvOS. The latest version of macOS is macOS10.12 Sierra, macOS is based on technologies developed at NeXT between 1985 and 1997, when Apple acquired the company. The X in Mac OS X and OS X is pronounced ten, macOS shares its Unix-based core, named Darwin, and many of its frameworks with iOS, tvOS and watchOS. A heavily modified version of Mac OS X10.4 Tiger was used for the first-generation Apple TV, Apple also used to have a separate line of releases of Mac OS X designed for servers. Beginning with Mac OS X10.7 Lion, the functions were made available as a separate package on the Mac App Store. Releases of Mac OS X from 1999 to 2005 can run only on the PowerPC-based Macs from the time period, Mac OS X10.5 Leopard was released as a Universal binary, meaning the installer disc supported both Intel and PowerPC processors. In 2009, Apple released Mac OS X10.6 Snow Leopard, in 2011, Apple released Mac OS X10.7 Lion, which no longer supported 32-bit Intel processors and also did not include Rosetta. All versions of the system released since then run exclusively on 64-bit Intel CPUs, the heritage of what would become macOS had originated at NeXT, a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, and then launched in 1989 and its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language. This led Apple to purchase NeXT in 1996, allowing NeXTSTEP, then called OPENSTEP, previous Macintosh operating systems were named using Arabic numerals, e. g. Mac OS8 and Mac OS9. The letter X in Mac OS Xs name refers to the number 10 and it is therefore correctly pronounced ten /ˈtɛn/ in this context. However, a common mispronunciation is X /ˈɛks/, consumer releases of Mac OS X included more backward compatibility. Mac OS applications could be rewritten to run natively via the Carbon API, the consumer version of Mac OS X was launched in 2001 with Mac OS X10.0. Reviews were variable, with praise for its sophisticated, glossy Aqua interface
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Application software
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An application program is a computer program designed to perform a group of coordinated functions, tasks, or activities for the benefit of the user. Examples of an application include a processor, a spreadsheet, an accounting application, a web browser, a media player, an aeronautical flight simulator. The collective noun application software refers to all applications collectively and this contrasts with system software, which is mainly involved with running the computer. Applications may be bundled with the computer and its software or published separately. Apps built for mobile platforms are called mobile apps, in information technology, an application is a computer program designed to help people perform an activity. An application thus differs from a system, a utility. Depending on the activity for which it was designed, an application can manipulate text, numbers, graphics, some application packages focus on a single task, such as word processing, others, called integrated software include several applications. User-written software tailors systems to meet the specific needs. User-written software includes templates, word processor macros, scientific simulations, graphics. Even email filters are a kind of user software, users create this software themselves and often overlook how important it is. The delineation between system software such as operating systems and application software is not exact, however, and is occasionally the object of controversy. As another example, the GNU/Linux naming controversy is, in part, the above definitions may exclude some applications that may exist on some computers in large organizations. For an alternative definition of an app, see Application Portfolio Management, the word application, once used as an adjective, is not restricted to the of or pertaining to application software meaning. Sometimes a new and popular application arises which only runs on one platform and this is called a killer application or killer app. There are many different ways to divide up different types of application software, web apps have indeed greatly increased in popularity for some uses, but the advantages of applications make them unlikely to disappear soon, if ever. Furthermore, the two can be complementary, and even integrated, Application software can also be seen as being either horizontal or vertical. Horizontal applications are more popular and widespread, because they are general purpose, vertical applications are niche products, designed for a particular type of industry or business, or department within an organization. Integrated suites of software will try to handle every aspect possible of, for example, manufacturing or banking systems, or accounting
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Rendering (computer graphics)
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Rendering or image synthesis is the process of generating an image from a 2D or 3D model by means of computer programs. Also, the results of such a model can be called a rendering, a scene file contains objects in a strictly defined language or data structure, it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene. The data contained in the file is then passed to a rendering program to be processed. The term rendering may be by analogy with a rendering of a scene. A GPU is a device able to assist a CPU in performing complex rendering calculations. If a scene is to look realistic and predictable under virtual lighting. The rendering equation doesnt account for all lighting phenomena, but is a lighting model for computer-generated imagery. Rendering is also used to describe the process of calculating effects in an editing program to produce final video output. Rendering is one of the major sub-topics of 3D computer graphics, in the graphics pipeline, it is the last major step, giving the final appearance to the models and animation. With the increasing sophistication of computer graphics since the 1970s, it has become a distinct subject. Rendering has uses in architecture, video games, simulators, movie or TV visual effects, as a product, a wide variety of renderers are available. Some are integrated into larger modeling and animation packages, some are stand-alone, on the inside, a renderer is a carefully engineered program, based on a selective mixture of disciplines related to, light physics, visual perception, mathematics, and software development. In the case of 3D graphics, rendering may be slowly, as in pre-rendering. When the pre-image is complete, rendering is used, which adds in bitmap textures or procedural textures, lights, bump mapping, the result is a completed image the consumer or intended viewer sees. For movie animations, several images must be rendered, and stitched together in a program capable of making an animation of this sort, most 3D image editing programs can do this. A rendered image can be understood in terms of a number of visible features, Rendering research and development has been largely motivated by finding ways to simulate these efficiently. Some relate directly to particular algorithms and techniques, while others are produced together, Tracing every particle of light in a scene is nearly always completely impractical and would take a stupendous amount of time. Even tracing a portion large enough to produce an image takes an amount of time if the sampling is not intelligently restricted
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Computer file
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A computer file is a computer resource for recording data discretely in a computer storage device. Just as words can be written to paper, so can information be written to a computer file, there are different types of computer files, designed for different purposes. A file may be designed to store a picture, a message, a video. Some types of files can store different several types of information at once, by using computer programs, a person can open, read, change, and close a computer file. Computer files may be reopened, modified, and copied a number of times. Typically, computer files are organised in a system, which keeps track of where the files are. The word file derives from the Latin filum, such a file now exists in a memory tube developed at RCA Laboratories. Electronically it retains figures fed into calculating machines, holds them in storage while it memorizes new ones - speeds intelligent solutions through mazes of mathematics, in 1952, file denoted, inter alia, information stored on punched cards. In early use, the hardware, rather than the contents stored on it, was denominated a file. For example, the IBM350 disk drives were denominated disk files, although the contemporary register file demonstrates the early concept of files, its use has greatly decreased. On most modern operating systems, files are organized into one-dimensional arrays of bytes, for example, the bytes of a plain text file are associated with either ASCII or UTF-8 characters, while the bytes of image, video, and audio files are interpreted otherwise. Most file types also allocate a few bytes for metadata, which allows a file to some basic information about itself. Some file systems can store arbitrary file-specific data outside of the file format, on other file systems this can be done via sidecar files or software-specific databases. All those methods, however, are susceptible to loss of metadata than are container. At any instant in time, a file might have a size, normally expressed as number of bytes, in most modern operating systems the size can be any non-negative whole number of bytes up to a system limit. Many older operating systems kept track only of the number of blocks or tracks occupied by a file on a storage device. In such systems, software employed other methods to track the exact byte count, the general definition of a file does not require that its size have any real meaning, however, unless the data within the file happens to correspond to data within a pool of persistent storage. A special case is a zero byte file, these files can be newly created files that have not yet had any data written to them, or may serve as some kind of flag in the file system, or are accidents
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Graphical user interface
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GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces, which require commands to be typed on a computer keyboard. The actions in a GUI are usually performed through direct manipulation of the graphical elements, beyond computers, GUIs are used in many handheld mobile devices such as MP3 players, portable media players, gaming devices, smartphones and smaller household, office and industrial controls. Designing the visual composition and temporal behavior of a GUI is an important part of application programming in the area of human–computer interaction. Its goal is to enhance the efficiency and ease of use for the logical design of a stored program. Methods of user-centered design are used to ensure that the language introduced in the design is well-tailored to the tasks. The visible graphical interface features of an application are sometimes referred to as chrome or GUI, typically, users interact with information by manipulating visual widgets that allow for interactions appropriate to the kind of data they hold. The widgets of an interface are selected to support the actions necessary to achieve the goals of users. A model–view–controller allows a structure in which the interface is independent from and indirectly linked to application functions. This allows users to select or design a different skin at will, good user interface design relates to users more, and to system architecture less. Large widgets, such as windows, usually provide a frame or container for the main presentation content such as a web page, smaller ones usually act as a user-input tool. A GUI may be designed for the requirements of a market as application-specific graphical user interfaces. By the 1990s, cell phones and handheld game systems also employed application specific touchscreen GUIs, newer automobiles use GUIs in their navigation systems and multimedia centers, or navigation multimedia center combinations. Sample graphical desktop environments A GUI uses a combination of technologies and devices to provide a platform that users can interact with, a series of elements conforming a visual language have evolved to represent information stored in computers. This makes it easier for people with few computer skills to work with, the most common combination of such elements in GUIs is the windows, icons, menus, pointer paradigm, especially in personal computers. The WIMP style of interaction uses a virtual device to represent the position of a pointing device, most often a mouse. Available commands are compiled together in menus, and actions are performed making gestures with the pointing device, a window manager facilitates the interactions between windows, applications, and the windowing system. The windowing system handles hardware devices such as pointing devices, graphics hardware, window managers and other software combine to simulate the desktop environment with varying degrees of realism. Smaller mobile devices such as personal assistants and smartphones typically use the WIMP elements with different unifying metaphors, due to constraints in space
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Icon (computing)
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In computing, an icon is a pictogram or ideogram displayed on a computer screen in order to help the user navigate a computer system or mobile device. It can serve as an electronic hyperlink or file shortcut to access the program or data, the user can activate an icon using a mouse, pointer, finger, or recently voice commands. Their placement on the screen, also in relation to other icons, in activating an icon, the user can move directly into and out of the identified function without knowing anything further about the location or requirements of the file or code. Graphically, the icon is a picture of objects that users are familiar with from office environment or from other professional arenas. One group of icons was taken from the symbols found across all devices, such as the power on/off symbol. Another group is metaphorically representing desktop objects from the 1980s office environment, a third group of icons are the brand icons used to identify commercial software programs. These commercial icons serve as links on the system to the program or data files created by a specific software provider. Although icons are depicted in graphical user interfaces, icons are sometimes rendered in a TUI using special characters such as MouseText or PETSCII. The design of all computer icons is constricted by the limitations of the device display and they are limited in size, with the standard size about a thumbnail for both desktop computer systems and mobile devices. They are frequently scalable, as they are displayed in different positions in the software, the colors used, of both the image and the icon background, should stand out on different system backgrounds. The detailing of the image needs to be simple, remaining recognizable in varying graphical resolutions. Computer icons are by definition language-independent, they do not rely on letters or words to convey their meaning and these visual parameters place rigid limits on the design of icons, frequently requiring the skills of a graphic artist in their development. Because of their size and versatility, computer icons have become a mainstay of user interaction with electronic media. Icons also provide rapid entry into the system functionality, on most systems, users can create and delete, replicate, select, click or double-click standard computer icons and drag them to new positions on the screen to create a customized user environment. Some common computer icons are taken from the field of standardized icons used across a wide range of electrical equipment. Examples of these are the symbol and the USB icon. The standardization of electronic icons is an important safety-feature on all types of electronics, as a subset of electronic devices, computer systems and mobile devices use many of the same icons, they are incorporated into the design of both the computer hardware and on the software. On the hardware, these identify the functionality of specific buttons
