A database is an organized collection of data stored and accessed electronically from a computer system. Where databases are more complex they are developed using formal design and modeling techniques; the database management system is the software that interacts with end users and the database itself to capture and analyze the data. The DBMS software additionally encompasses; the sum total of the database, the DBMS and the associated applications can be referred to as a "database system". The term "database" is used to loosely refer to any of the DBMS, the database system or an application associated with the database. Computer scientists may classify database-management systems according to the database models that they support. Relational databases became dominant in the 1980s; these model data as rows and columns in a series of tables, the vast majority use SQL for writing and querying data. In the 2000s, non-relational databases became popular, referred to as NoSQL because they use different query languages.
Formally, a "database" refers to the way it is organized. Access to this data is provided by a "database management system" consisting of an integrated set of computer software that allows users to interact with one or more databases and provides access to all of the data contained in the database; the DBMS provides various functions that allow entry and retrieval of large quantities of information and provides ways to manage how that information is organized. Because of the close relationship between them, the term "database" is used casually to refer to both a database and the DBMS used to manipulate it. Outside the world of professional information technology, the term database is used to refer to any collection of related data as size and usage requirements necessitate use of a database management system. Existing DBMSs provide various functions that allow management of a database and its data which can be classified into four main functional groups: Data definition – Creation and removal of definitions that define the organization of the data.
Update – Insertion and deletion of the actual data. Retrieval – Providing information in a form directly usable or for further processing by other applications; the retrieved data may be made available in a form the same as it is stored in the database or in a new form obtained by altering or combining existing data from the database. Administration – Registering and monitoring users, enforcing data security, monitoring performance, maintaining data integrity, dealing with concurrency control, recovering information, corrupted by some event such as an unexpected system failure. Both a database and its DBMS conform to the principles of a particular database model. "Database system" refers collectively to the database model, database management system, database. Physically, database servers are dedicated computers that hold the actual databases and run only the DBMS and related software. Database servers are multiprocessor computers, with generous memory and RAID disk arrays used for stable storage.
RAID is used for recovery of data. Hardware database accelerators, connected to one or more servers via a high-speed channel, are used in large volume transaction processing environments. DBMSs are found at the heart of most database applications. DBMSs may be built around a custom multitasking kernel with built-in networking support, but modern DBMSs rely on a standard operating system to provide these functions. Since DBMSs comprise a significant market and storage vendors take into account DBMS requirements in their own development plans. Databases and DBMSs can be categorized according to the database model that they support, the type of computer they run on, the query language used to access the database, their internal engineering, which affects performance, scalability and security; the sizes and performance of databases and their respective DBMSs have grown in orders of magnitude. These performance increases were enabled by the technology progress in the areas of processors, computer memory, computer storage, computer networks.
The development of database technology can be divided into three eras based on data model or structure: navigational, SQL/relational, post-relational. The two main early navigational data models were the hierarchical model and the CODASYL model The relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links; the relational model employs sets of ledger-style tables, each used for a different type of entity. Only in the mid-1980s did computing hardware become powerful enough to allow the wide deployment of relational systems. By the early 1990s, relational systems dominated in all large-scale data processing applications, as of 2018 they remain dominant: IBM DB2, Oracle, MySQL, Microsoft SQL Server are the most searched DBMS; the dominant database language, standardised SQL for the relational model, has influenced database languages for other data models. Object databases were developed in the 1980s to overcome the inconvenience of object-relational impedance mismatch, which led to the coining of the term "post-relational" and the development of hybrid object-relational databas
Reversi is a strategy board game for two players, played on an 8×8 uncheckered board. There are sixty-four identical game pieces called disks, which are light on one side and dark on the other. Players take. During a play, any disks of the opponent's color that are in a straight line and bounded by the disk just placed and another disk of the current player's color are turned over to the current player's color; the object of the game is to have the majority of disks turned to display your color when the last playable empty square is filled. Reversi was most marketed by Mattel under the trademark Othello; the game Reversi was invented in 1883 by either of two Englishmen, Lewis Waterman or John W. Mollett, gained considerable popularity in England at the end of the nineteenth century; the game's first reliable mention is in the 21 August 1886 edition of The Saturday Review. Mention includes an 1895 article in The New York Times: "Reversi is something like Go Bang, is played with 64 pieces." In 1893, the German games publisher Ravensburger started producing the game as one of its first titles.
Two 18th-century continental European books dealing with a game that may or may not be Reversi are mentioned on page fourteen of the Spring 1989 Othello Quarterly, there has been speculation, so far without documentation, that the game has older origins. The modern version of the game — the most used rule-set, the one used in international tournaments — is marketed and recognized as Othello, it was patented in Japan in 1971 by Goro Hasegawa a 38-year-old salesman. There is one difference from the original game: The first four pieces go in the center, but in a standard diagonal pattern, rather than being placed by players. According to Ben Seeley, another difference of Reversi from Othello is that in the first one the game ends as soon as either player cannot make a move, while in the latter the player without a move passes. Hasegawa established the Japan Othello Association on March 1973, held the first national Othello championship on April 4, 1973 in Japan; the Japanese game company Tsukuda Original launched Othello in late April, 1973 in Japan under Hasegawa’s license, which led to an immediate commercial success.
The name was selected by Hasegawa as a reference to the Shakespearean play Othello, the Moor of Venice, referring to the conflict between the Moor Othello and Iago, more controversially, to the unfolding drama between Othello, black, Desdemona, white. The green color of the board is inspired by the image of the general Othello, valiantly leading his battle in a green field, it can be likened to a jealousy competition, since players engulf the pieces of the opponent, thereby turning them to their possession. Othello was first launched in the U. S. in 1975 by Gabriel Industries and it enjoyed commercial success there. Othello game sales have exceeded $600 million and more than 40 million classic games have been sold in over 100 different countries. Hasegawa wrote How to Othello in Japan in 1974, translated into English and published in the U. S. in 1977 as How to Win at Othello. Kabushiki Kaisha Othello, owned by Hasegawa, registered the trademark "OTHELLO" for board games in Japan and Tsukuda Original registered the mark in the rest of the world.
All intellectual property regarding Othello outside Japan is now owned by MegaHouse, a Japanese toy company that acquired PalBox, the successor to Tsukuda Original. Each of the disks' two sides corresponds to one player; the game may for example be played with a chessboard and Scrabble pieces, with one player letters and the other backs. The historical version of Reversi starts with an empty board, the first two moves by each player are in the four central squares of the board; the players place their disks alternately with their color facing up and no captures are made. A player may choose to not play both pieces on the same diagonal, different from the standard Othello opening, it is possible to play variants of Reversi and Othello wherein the second player's second move may or must flip one of the opposite-colored disks. For the specific game of Othello, the rules state that the game begins with four disks placed in a square in the middle of the grid, two facing white side up, two pieces with the dark side up, with same-colored disks on a diagonal with each other.
Convention has initial board position such that the disks with dark side up are to the north-east and south-west, though this is only marginally meaningful to play. If the disks with dark side up are to the north-west and south-east, the board may be rotated by 90° clockwise or counterclockwise; the dark player moves first. Dark must place a piece with the dark side up on the board, in such a position that there exists at least one straight occupied line between the new piece and another dark piece, with one or more contiguous light pieces between them. In the below situation, dark has the following options indicated by translucent pieces: After placing the piece, dark turns over all light pieces lying on a straight line b
The Intel 80286 is a 16-bit microprocessor, introduced on February 1, 1982. It was the first 8086-based CPU with separate, non-multiplexed address and data buses and the first with memory management and wide protection abilities; the 80286 used 134,000 transistors in its original nMOS incarnation and, just like the contemporary 80186, it could execute most software written for the earlier Intel 8086 and 8088 processors. The 80286 was employed for the IBM PC/AT, introduced in 1984, widely used in most PC/AT compatible computers until the early 1990s. Intel's first 80286 chips were specified for a maximum clockrate of 4, 6 or 8 MHz and releases for 12.5 MHz. AMD and Harris produced 16 MHz, 20 MHz and 25 MHz parts, respectively. Intersil and Fujitsu designed static CMOS versions of Intel's original depletion-load nMOS implementation aimed at battery-powered devices. On average, the 80286 was measured to have a speed of about 0.21 instructions per clock on "typical" programs, although it could be faster on optimized code and in tight loops, as many instructions could execute in 2 clock cycles each.
The 6 MHz, 10 MHz and 12 MHz models were measured to operate at 0.9 MIPS, 1.5 MIPS and 2.66 MIPS respectively. The E-stepping level of the 80286 was free of the several significant errata that caused problems for programmers and operating-system writers in the earlier B-step and C-step CPUs; the 80286 was designed for multi-user systems with multitasking applications, including communications and real-time process control. It had 134,000 transistors and consisted of four independent units: address unit, bus unit, instruction unit and execution unit, organized into a loosely coupled pipeline just as in the 8086; the increased performance over the 8086 was due to the non-multiplexed address and data buses, more address-calculation hardware and a faster multiplier. It was produced in a 68-pin package, including LCC and PGA packages; the performance increase of the 80286 over the 8086 could be more than 100% per clock cycle in many programs. This was a large increase comparable to the speed improvements around a decade when the i486 or the original Pentium were introduced.
This was due to the non-multiplexed address and data buses, but to the fact that address calculations were less expensive. They were performed by a dedicated unit in the 80286, while the older 8086 had to do effective address computation using its general ALU, consuming several extra clock cycles in many cases; the 80286 was more efficient in the prefetch of instructions, execution of jumps, in complex microcoded numerical operations such as MUL/DIV than its predecessor. The 80286 included, in addition to all of the 8086 instructions, all of the new instructions of the 80186: ENTER, LEAVE, BOUND, INS, OUTS, PUSHA, POPA, PUSH immediate, IMUL immediate, immediate shifts and rotates; the 80286 added new instructions for protected mode: ARPL, CLTS, LAR, LGDT, LIDT, LLDT, LMSW, LSL, LTR, SGDT, SIDT, SLDT, SMSW, STR, VERR, VERW. Some of the instructions for protected mode can be used in real mode to set up and switch to protected mode, a few are useful for real mode itself; the Intel 80286 had a 24-bit address bus and was able to address up to 16 MB of RAM, compared to the 1 MB addressability of its predecessor.
However, memory cost and the initial rarity of software using the memory above 1 MB meant that 80286 computers were shipped with more than one megabyte of RAM. Additionally, there was a performance penalty involved in accessing extended memory from real mode, as noted below; the 286 was the first of the x86 CPU family to support protected virtual-address mode called "protected mode". In addition, it was the first commercially available microprocessor with on-chip MMU capabilities; this would allow IBM compatibles to have advanced multitasking OSes for the first time and compete in the Unix-dominated server/workstation market. Several additional instructions were introduced in protected mode of 80286, which are helpful for multitasking operating systems. Another important feature of 80286 is prevention of unauthorized access; this is achieved by: Forming different segments for data and stack, preventing their overlapping. Assigning privilege levels to each segment. Segment with lower privilege level cannot access the segment with higher privilege level.
In 80286, arithmetic operations can be performed on the following different types of numbers: unsigned packed decimal, unsigned binary, unsigned unpacked decimal, signed binary, floating-point numbers. By design, the 286 could not revert from protected mode to the basic 8086-compatible real address mode without a hardware-initiated reset. In the PC/AT introduced in 1984, IBM added external circuitry, as well as specialized code in the ROM BIOS and the 8042 peripheral microcontroller to enable software to cause the reset, allowing real-mode reentry while retaining active memory and returning control to the program that initiated the reset. (The BIOS is involved because it obtains control di
An embedded system is a controller programmed and controlled by a real-time operating system with a dedicated function within a larger mechanical or electrical system with real-time computing constraints. It is embedded as part of a complete device including hardware and mechanical parts. Embedded systems control many devices in common use today. Ninety-eight percent of all microprocessors manufactured are used in embedded systems. Examples of properties of typical embedded computers when compared with general-purpose counterparts are low power consumption, small size, rugged operating ranges, low per-unit cost; this comes at the price of limited processing resources, which make them more difficult to program and to interact with. However, by building intelligence mechanisms on top of the hardware, taking advantage of possible existing sensors and the existence of a network of embedded units, one can both optimally manage available resources at the unit and network levels as well as provide augmented functions, well beyond those available.
For example, intelligent techniques can be designed to manage power consumption of embedded systems. Modern embedded systems are based on microcontrollers, but ordinary microprocessors are common in more complex systems. In either case, the processor used may be types ranging from general purpose to those specialized in certain class of computations, or custom designed for the application at hand. A common standard class of dedicated processors is the digital signal processor. Since the embedded system is dedicated to specific tasks, design engineers can optimize it to reduce the size and cost of the product and increase the reliability and performance; some embedded systems are mass-produced. Embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, factory controllers, complex systems like hybrid vehicles, MRI, avionics. Complexity varies from low, with a single microcontroller chip, to high with multiple units and networks mounted inside a large chassis or enclosure.
One of the first recognizably modern embedded systems was the Apollo Guidance Computer, developed ca. 1965 by Charles Stark Draper at the MIT Instrumentation Laboratory. At the project's inception, the Apollo guidance computer was considered the riskiest item in the Apollo project as it employed the newly developed monolithic integrated circuits to reduce the size and weight. An early mass-produced embedded system was the Autonetics D-17 guidance computer for the Minuteman missile, released in 1961; when the Minuteman II went into production in 1966, the D-17 was replaced with a new computer, the first high-volume use of integrated circuits. Since these early applications in the 1960s, embedded systems have come down in price and there has been a dramatic rise in processing power and functionality. An early microprocessor for example, the Intel 4004, was designed for calculators and other small systems but still required external memory and support chips. In 1978 National Engineering Manufacturers Association released a "standard" for programmable microcontrollers, including any computer-based controllers, such as single board computers and event-based controllers.
As the cost of microprocessors and microcontrollers fell it became feasible to replace expensive knob-based analog components such as potentiometers and variable capacitors with up/down buttons or knobs read out by a microprocessor in consumer products. By the early 1980s, memory and output system components had been integrated into the same chip as the processor forming a microcontroller. Microcontrollers find applications. A comparatively low-cost microcontroller may be programmed to fulfill the same role as a large number of separate components. Although in this context an embedded system is more complex than a traditional solution, most of the complexity is contained within the microcontroller itself. Few additional components may be needed and most of the design effort is in the software. Software prototype and test can be quicker compared with the design and construction of a new circuit not using an embedded processor. Embedded systems are found in consumer, automotive, medical and military applications.
Telecommunications systems employ numerous embedded systems from telephone switches for the network to cell phones at the end user. Computer networking uses dedicated routers and network bridges to route data. Consumer electronics include MP3 players, mobile phones, video game consoles, digital cameras, GPS receivers, printers. Household appliances, such as microwave ovens, washing machines and dishwashers, include embedded systems to provide flexibility and features. Advanced HVAC systems use networked thermostats to more and efficiently control temperature that can change by time of day and season. Home automation uses wired- and wireless-networking that can be used to control lights, security, audio/visual, etc. all of which use embedded devices for sensing and controlling. Transportation systems from flight to automobiles use embedded systems. New airplanes contain advanced avionics such as inertial guidance systems and GPS receivers that have considerable safety requirements. Various electric motors — brushless DC motors, induction motors and DC motors — use electric/electronic motor controllers.
Automobiles, electric vehicles, hy
Backward compatibility is a property of a system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system in telecommunications and computing. Backward compatibility is sometimes called downward compatibility. Modifying a system in a way that does not allow backward compatibility is sometimes called "breaking" backward compatibility. A complementary concept is forward compatibility. A design, forward-compatible has a roadmap for compatibility with future standards and products; the associated benefits of backward compatibility are the appeal to an existing user base through an inexpensive upgrade path as well as the network effect, important, as it increases the value of goods and services proportionally to the size of the user base. One example of this is the Sony PlayStation 2, backward compatible with games for its predecessor PlayStation. While the selection of PS2 games available at launch was small, sales of the console were nonetheless strong in 2000-2001 thanks to the large library of games for the preceding PS1.
This bought time for the PS2 to grow a large installed base and developers to release more quality PS2 games for the crucial 2001 holiday season. The associated costs of backward compatibility are a higher bill of materials if hardware is required to support the legacy systems. A notable example is the Sony PlayStation 3, as the first PS3 iteration was expensive to manufacture in part due to including the Emotion Engine from the preceding PS2 in order to run PS2 games, since the PS3 architecture was different from the PS2. Subsequent PS3 hardware revisions have eliminated the Emotion Engine as it saved production costs while removing the ability to run PS2 titles, as Sony found out that backward compatibility was not a major selling point for the PS3. in contrast to the PS2. The PS3's chief competitor, the Microsoft Xbox 360, took a different approach to backward compatibility by using software emulation in order to run games from the first Xbox, rather than including legacy hardware from the original Xbox, quite different than the Xbox 360, however Microsoft stopped releasing emulation profiles after 2007.
A simple example of both backward and forward compatibility is the introduction of FM radio in stereo. FM radio was mono, with only one audio channel represented by one signal. With the introduction of two-channel stereo FM radio, a large number of listeners had only mono FM receivers. Forward compatibility for mono receivers with stereo signals was achieved through sending the sum of both left and right audio channels in one signal and the difference in another signal; that allows mono FM receivers to receive and decode the sum signal while ignoring the difference signal, necessary only for separating the audio channels. Stereo FM receivers can receive a mono signal and decode it without the need for a second signal, they can separate a sum signal to left and right channels if both sum and difference signals are received. Without the requirement for backward compatibility, a simpler method could have been chosen. Full backward compatibility is important in computer instruction set architectures, one of the most successful being the x86 family of microprocessors.
Their full backward compatibility spans back to the 16-bit Intel 8086/8088 processors introduced in 1978. Backwards compatible processors can process the same binary executable software instructions as their predecessors, allowing the use of a newer processor without having to acquire new applications or operating systems; the success of the Wi-Fi digital communication standard is attributed to its broad forward and backward compatibility. Compiler backward compatibility may refer to the ability of a compiler of a newer version of the language to accept programs or data that worked under the previous version. A data format is said to be backward compatible with its predecessor if every message or file, valid under the old format is still valid, retaining its meaning under the new format
Microsoft Corporation is an American multinational technology company with headquarters in Redmond, Washington. It develops, licenses and sells computer software, consumer electronics, personal computers, related services, its best known software products are the Microsoft Windows line of operating systems, the Microsoft Office suite, the Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface lineup of touchscreen personal computers; as of 2016, it is the world's largest software maker by revenue, one of the world's most valuable companies. The word "Microsoft" is a portmanteau of "microcomputer" and "software". Microsoft is ranked No. 30 in the 2018 Fortune 500 rankings of the largest United States corporations by total revenue. Microsoft was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for the Altair 8800, it rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Microsoft Windows.
The company's 1986 initial public offering, subsequent rise in its share price, created three billionaires and an estimated 12,000 millionaires among Microsoft employees. Since the 1990s, it has diversified from the operating system market and has made a number of corporate acquisitions, their largest being the acquisition of LinkedIn for $26.2 billion in December 2016, followed by their acquisition of Skype Technologies for $8.5 billion in May 2011. As of 2015, Microsoft is market-dominant in the IBM PC-compatible operating system market and the office software suite market, although it has lost the majority of the overall operating system market to Android; the company produces a wide range of other consumer and enterprise software for desktops and servers, including Internet search, the digital services market, mixed reality, cloud computing and software development. Steve Ballmer replaced Gates as CEO in 2000, envisioned a "devices and services" strategy; this began with the acquisition of Danger Inc. in 2008, entering the personal computer production market for the first time in June 2012 with the launch of the Microsoft Surface line of tablet computers.
Since Satya Nadella took over as CEO in 2014, the company has scaled back on hardware and has instead focused on cloud computing, a move that helped the company's shares reach its highest value since December 1999. In 2018, Microsoft surpassed Apple as the most valuable publicly traded company in the world after being dethroned by the tech giant in 2010. Childhood friends Bill Gates and Paul Allen sought to make a business utilizing their shared skills in computer programming. In 1972 they founded their first company, named Traf-O-Data, which sold a rudimentary computer to track and analyze automobile traffic data. While Gates enrolled at Harvard, Allen pursued a degree in computer science at Washington State University, though he dropped out of school to work at Honeywell; the January 1975 issue of Popular Electronics featured Micro Instrumentation and Telemetry Systems's Altair 8800 microcomputer, which inspired Allen to suggest 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 didn't yet have one, Allen worked on a simulator for the Altair while Gates developed the interpreter. Although they developed the interpreter on a simulator and not the actual device, it worked flawlessly when they demonstrated the interpreter to MITS in Albuquerque, New Mexico. MITS agreed to distribute it, marketing it as Altair BASIC. Gates and Allen established Microsoft on April 4, 1975, with Gates as the CEO; the original name of "Micro-Soft" was suggested by Allen. In August 1977 the company formed an agreement with ASCII Magazine in Japan, resulting in its first international office, "ASCII Microsoft". Microsoft moved to a new home in Bellevue, Washington in January 1979. Microsoft entered the operating system business in 1980 with its own version of Unix, called Xenix. However, it was MS-DOS. After negotiations with Digital Research failed, IBM awarded a contract to Microsoft in November 1980 to provide a version of the CP/M OS, set to be used in the upcoming IBM Personal Computer.
For this deal, Microsoft purchased a CP/M clone called 86-DOS from Seattle Computer Products, which it branded as MS-DOS, though IBM rebranded it to PC DOS. Following the release of the IBM PC in August 1981, Microsoft retained ownership of MS-DOS. Since IBM had copyrighted the IBM PC BIOS, other companies had to reverse engineer it in order for non-IBM hardware to run as IBM PC compatibles, but no such restriction applied to the operating systems. Due to various factors, such as MS-DOS's available software selection, Microsoft became the leading PC operating systems vendor; 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 Hodgkin's disease. Allen claimed that Gates wanted to dilute his share in the company when he was diagnosed with Hodgkin's disease because he didn't think he was working hard enough. After leaving Microsoft, Allen lost billions of dollars on ill-conceived or mistimed technology investments.
He invested in low-tech sectors, sports teams, commercial real estate. Despite having begun jointly developing a new operating system, OS/2, with IBM in
Microsoft Windows is a group of several graphical operating system families, all of which are developed and sold by Microsoft. Each family caters to a certain sector of the computing industry. Active Windows families include Windows Embedded. Defunct Windows families include Windows Mobile and Windows Phone. Microsoft introduced an operating environment named Windows on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces. Microsoft Windows came to dominate the world's personal computer market with over 90% market share, overtaking Mac OS, introduced in 1984. Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh. 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 %. This comparison however may not be relevant, as the two operating systems traditionally target different platforms. Still, numbers for server use of Windows show one third market share, similar to that for end user use; as of October 2018, the most recent version of Windows for PCs, tablets and embedded devices is Windows 10. The most recent versions for server computers is Windows Server 2019. A specialized version of Windows runs on the Xbox One video 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; as of 2014, the following Windows families are being developed: Windows NT: Started as a family of operating systems with Windows NT 3.1, an operating system for server computers and workstations. It now consists of three operating system subfamilies that are released at the same time and share the same kernel: Windows: The operating system for mainstream personal computers and smartphones.
The latest version is Windows 10. The main competitor of this family is macOS by Apple for personal computers and Android for mobile devices. Windows Server: The operating system for server computers; the latest version is Windows Server 2019. Unlike its client 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 a live operating system, used for installing Windows on bare-metal computers, recovery or troubleshooting purposes; the latest version is Windows PE 10. Windows IoT: Initially, Microsoft developed Windows CE as a general-purpose operating system for every device, too resource-limited to be called a full-fledged computer. However, Windows CE was renamed Windows Embedded Compact and was folded under Windows Compact trademark which consists of Windows Embedded Industry, Windows Embedded Professional, Windows Embedded Standard, Windows Embedded Handheld and Windows Embedded Automotive.
The following Windows families are no longer being developed: Windows 9x: An operating system that targeted consumers market. Discontinued because of suboptimal performance. Microsoft now caters to the consumer market with Windows NT. Windows Mobile: The predecessor to Windows Phone, it was a mobile phone operating system; the first version was called Pocket PC 2000. The last version is Windows Mobile 6.5. Windows Phone: An operating system sold only to manufacturers of smartphones; the first version was Windows Phone 7, followed by Windows Phone 8, the last version Windows Phone 8.1. It was succeeded by Windows 10 Mobile; the term Windows collectively describes any or all of several generations of Microsoft operating system products. These products are categorized as follows: The history of Windows dates back to 1981, when Microsoft started work on a program called "Interface Manager", it was announced in November 1983 under the name "Windows", but Windows 1.0 was not released until November 1985.
Windows 1.0 was to achieved little popularity. Windows 1.0 is not a complete operating system. The shell of Windows 1.0 is a program known as the MS-DOS Executive. Components included Calculator, Cardfile, Clipboard viewer, Control Panel, Paint, Reversi and Write. Windows 1.0 does not allow overlapping windows. Instead all windows are tiled. Only modal dialog boxes may appear over other windows. Microsoft sold as included Windows Development libraries with the C development environment, which included numerous windows samples. Windows 2.0 was released in December 1987, was more popular than its predecessor. It features several improvements to the user memory management. Windows 2.03 changed the OS from tiled windows to overlapping windows. The result of this change led to Apple Computer filing a suit against Microsoft alleging infringement on Apple's copyrights. Windows 2.0