Application software is software designed to perform a group of coordinated functions, tasks, or activities for the benefit of the user. Examples of an application include a word processor, a spreadsheet, an accounting application, a web browser, an email client,a media player, a file viewer, an aeronautical flight simulator, a console game or a photo editor; the collective noun application software refers to all applications collectively. This contrasts with system software, involved with running the computer. Applications may be bundled with the computer and its system software or published separately, may be coded as proprietary, open-source or university projects. Apps built for mobile platforms are called mobile apps. In information technology, an application, application program or software application is a computer program designed to help people perform an activity. An application thus differs from an operating system, a utility, a programming tool. Depending on the activity for which it was designed, an application can manipulate text, audio, graphics, or a combination of these elements.
Some application packages focus on a single task, such as word processing. User-written software tailors systems to meet the user's specific needs. User-written software includes spreadsheet templates, word processor macros, scientific simulations, audio and animation scripts. Email filters are a kind of user software. Users create this software themselves and overlook how important it is; the delineation between system software such as operating systems and application software is not exact, is the object of controversy. For example, one of the key questions in the United States v. Microsoft Corp. antitrust trial was whether Microsoft's Internet Explorer web browser was part of its Windows operating system or a separable piece of application software. As another example, the GNU/Linux naming controversy is, in part, due to disagreement about the relationship between the Linux kernel and the operating systems built over this kernel. In some types of embedded systems, the application software and the operating system software may be indistinguishable to the user, as in the case of software used to control a VCR, DVD player or microwave oven.
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. For example, concepts such as application programming interface, application server, application virtualization, application lifecycle management and portable application apply to all computer programs alike, not just application software; some applications are available in versions for several different platforms. Sometimes a new and popular application arises which only runs on one platform, increasing the desirability of that platform; this is called a killer killer app. For example, VisiCalc was the first modern spreadsheet software for the Apple II and helped selling the then-new personal computers into offices. For Blackberry it was their email software. In recent years, the shortened term "app" has become popular to refer to applications for mobile devices such as smartphones and tablets, the shortened form matching their smaller scope compared to applications on PCs.
More the shortened version is used for desktop application software as well. There are many different and not alternative ways in order to order and classify application software. By the legal point of view, application software is classified with a black box approach, in relation to the rights of its final end-users or subscribers. Software applications are classified in respect of the programming language in which the source code is written or executed, respect of their purpose and outputs. Application software is distinguished among two main classes: closed source vs open source software applications, among free or proprietary software applications. Proprietary software is placed under the exclusive copyright, a software license grants limited usage rights; the open-closed principle states that software may be "open only for extension, but not for modification". Such applications can only get add-on by third-parties. Free and open-source software shall be run, sold or extended for any purpose, -being open- shall be modified or reversed in the same way.
Metadata is "data that provides information about other data". Many distinct types of metadata exist, among these descriptive metadata, structural metadata, administrative metadata, reference metadata and statistical metadata. Descriptive metadata describes a resource for purposes such as identification, it can include elements such as title, abstract and keywords. Structural metadata is metadata about containers of data and indicates how compound objects are put together, for example, how pages are ordered to form chapters, it describes the types, versions and other characteristics of digital materials. Administrative metadata provides information to help manage a resource, such as when and how it was created, file type and other technical information, who can access it. Reference metadata describes the contents and quality of statistical data Statistical metadata may describe processes that collect, process, or produce statistical data. Metadata was traditionally used in the card catalogs of libraries until the 1980s, when libraries converted their catalog data to digital databases.
In the 2000s, as digital formats were becoming the prevalent way of storing data and information, metadata was used to describe digital data using metadata standards. The first description of "meta data" for computer systems is purportedly noted by MIT's Center for International Studies experts David Griffel and Stuart McIntosh in 1967: "In summary we have statements in an object language about subject descriptions of data and token codes for the data. We have statements in a meta language describing the data relationships and transformations, ought/is relations between norm and data."There are different metadata standards for each different discipline. Describing the contents and context of data or data files increases its usefulness. For example, a web page may include metadata specifying what software language the page is written in, what tools were used to create it, what subjects the page is about, where to find more information about the subject; this metadata can automatically improve the reader's experience and make it easier for users to find the web page online.
A CD may include metadata providing information about the musicians and songwriters whose work appears on the disc. A principal purpose of metadata is to help users discover resources. Metadata helps to organize electronic resources, provide digital identification, support the archiving and preservation of resources. Metadata assists users in resource discovery by "allowing resources to be found by relevant criteria, identifying resources, bringing similar resources together, distinguishing dissimilar resources, giving location information." Metadata of telecommunication activities including Internet traffic is widely collected by various national governmental organizations. This data can be used for mass surveillance. In many countries, the metadata relating to emails, telephone calls, web pages, video traffic, IP connections and cell phone locations are stored by government organizations. Metadata means "data about data". Although the "meta" prefix means "after" or "beyond", it is used to mean "about" in epistemology.
Metadata is defined as the data providing information about one or more aspects of the data. Some examples include:Means of creation of the data Purpose of the data Time and date of creation Creator or author of the data Location on a computer network where the data was created Standards used File size Data quality Source of the data Process used to create the dataFor example, a digital image may include metadata that describes how large the picture is, the color depth, the image resolution, when the image was created, the shutter speed, other data. A text document's metadata may contain information about how long the document is, who the author is, when the document was written, a short summary of the document. Metadata within web pages can contain descriptions of page content, as well as key words linked to the content; these links are called "Metatags", which were used as the primary factor in determining order for a web search until the late 1990s. The reliance of metatags in web searches was decreased in the late 1990s because of "keyword stuffing".
Metatags were being misused to trick search engines into thinking some websites had more relevance in the search than they did. Metadata can be stored and managed in a database called a metadata registry or metadata repository. However, without context and a point of reference, it might be impossible to identify metadata just by looking at it. For example: by itself, a database containing several numbers, all 13 digits long could be the results of calculations or a list of numbers to plug into an equation - without any other context, the numbers themselves can be perceived as the data, but if given the context that this database is a log of a book collection, those 13-digit numbers may now be identified as ISBNs - information that refers to the book, but is not itself the information within the book. The term "metadata" was coined in 1968 by Philip Bagley, in his book "Extension of Programming Language Concepts" where it is clear that he uses the term in the ISO 11179 "traditional" sense, "structural metadata" i.e. "data about the containers of data".
A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to properties of the real world entities. For instance, a data model may specify that the data element representing a car be composed of a number of other elements which, in turn, represent the color and size of the car and define its owner; the term data model is used in two distinct but related senses. Sometimes it refers to an abstract formalization of the objects and relationships found in a particular application domain, for example the customers and orders found in a manufacturing organization. At other times it refers to a set of concepts used in defining such formalizations: for example concepts such as entities, relations, or tables. So the "data model" of a banking application may be defined using the entity-relationship "data model"; this article uses the term in both senses. A data model explicitly determines the structure of data. Data models are specified in a data modeling notation, graphical in form.
A data model can sometimes be referred to as a data structure in the context of programming languages. Data models are complemented by function models in the context of enterprise models. Managing large quantities of structured and unstructured data is a primary function of information systems. Data models describe the structure and integrity aspects of the data stored in data management systems such as relational databases, they do not describe unstructured data, such as word processing documents, email messages, digital audio, video. The main aim of data models is to support the development of information systems by providing the definition and format of data. According to West and Fowler "if this is done across systems compatibility of data can be achieved. If the same data structures are used to store and access data different applications can share data; the results of this are indicated above. However and interfaces cost more than they should, to build and maintain, they may constrain the business rather than support it.
A major cause is that the quality of the data models implemented in systems and interfaces is poor". "Business rules, specific to how things are done in a particular place, are fixed in the structure of a data model. This means that small changes in the way business is conducted lead to large changes in computer systems and interfaces". "Entity types are not identified, or incorrectly identified. This can lead to replication of data, data structure, functionality, together with the attendant costs of that duplication in development and maintenance". "Data models for different systems are arbitrarily different. The result of this is; these interfaces can account for between 25-70% of the cost of current systems". "Data cannot be shared electronically with customers and suppliers, because the structure and meaning of data has not been standardized. For example, engineering design data and drawings for process plant are still sometimes exchanged on paper"; the reason for these problems is a lack of standards that will ensure that data models will both meet business needs and be consistent.
A data model explicitly determines the structure of data. Typical applications of data models include database models, design of information systems, enabling exchange of data. Data models are specified in a data modeling language. A data model instance may be one of three kinds according to ANSI in 1975: Conceptual data model: describes the semantics of a domain, being the scope of the model. For example, it may be a model of the interest area of an industry; this consists of entity classes, representing kinds of things of significance in the domain, relationship assertions about associations between pairs of entity classes. A conceptual schema specifies the kinds of facts or propositions that can be expressed using the model. In that sense, it defines the allowed expressions in an artificial'language' with a scope, limited by the scope of the model. Logical data model: describes the semantics, as represented by a particular data manipulation technology; this consists of descriptions of tables and columns, object oriented classes, XML tags, among other things.
Physical data model: describes the physical means. This is concerned with partitions, CPUs, the like; the significance of this approach, according to ANSI, is that it allows the three perspectives to be independent of each other. Storage technology can change without affecting the conceptual model; the table/column structure can change without affecting the conceptual model. In each case, of course, the structures must remain consistent with the other model; the table/column structure may be different from a direct translation of the entity classes and attributes, but it must carry out the objectives of the conceptual entity class structure. Early phases of many software development projects emphasize the design of a conceptual data model; such a design can be detailed into a logical data model. In stages, this model may be translated into physical data model. However, it is possible to implement a conceptual model directly. One of the earliest pioneering works in modelling information systems was done by Young and Kent, who argued for "a precise and abstract way of specifying the informational and time characteristics of a data processing problem".
They wanted to create "a notation that should enable the analyst to organize the problem around any piece of hardwa
Information is the resolution of uncertainty. Information is associated with data and knowledge, as data is meaningful information and represents the values attributed to parameters, knowledge signifies understanding of an abstract or concrete concept; the existence of information can be uncoupled from an observer, which refers to that which accesses information to discern that which it specifies. In the case of knowledge, the information itself requires a cognitive observer to be accessed. In terms of communication, information is expressed either as the content of a message or through direct or indirect observation. That, perceived can be construed as a message in its own right, in that sense, information is always conveyed as the content of a message. Information can be encoded into various forms for interpretation, it can be encrypted for safe storage and communication. Information reduces uncertainty; the uncertainty of an event is measured by its probability of occurrence and is inversely proportional to that.
The more uncertain an event, the more information is required to resolve uncertainty of that event. The bit is a typical unit of information. For example, the information encoded in one "fair" coin flip is log2 = 1 bit, in two fair coin flips is log2 = 2 bits; the concept of information has different meanings in different contexts. Thus the concept becomes related to notions of constraint, control, form, knowledge, understanding, mental stimuli, perception and entropy; the English word derives from the Latin stem of the nominative: this noun derives from the verb informare in the sense of "to give form to the mind", "to discipline", "instruct", "teach". Inform itself comes from the Latin verb informare, which means to form an idea of. Furthermore, Latin itself contained the word informatio meaning concept or idea, but the extent to which this may have influenced the development of the word information in English is not clear; the ancient Greek word for form was μορφή and εἶδος "kind, shape, set", the latter word was famously used in a technical philosophical sense by Plato to denote the ideal identity or essence of something.'Eidos' can be associated with thought, proposition, or concept.
The ancient Greek word for information is πληροφορία, which transliterates from πλήρης "fully" and φέρω frequentative of to carry through. It means "bears fully" or "conveys fully". In modern Greek the word Πληροφορία is still in daily use and has the same meaning as the word information in English. In addition to its primary meaning, the word Πληροφορία as a symbol has deep roots in Aristotle's semiotic triangle. In this regard it can be interpreted to communicate information to the one decoding that specific type of sign; this is something that occurs with the etymology of many words in ancient and modern Greek where there is a strong denotative relationship between the signifier, e.g. the word symbol that conveys a specific encoded interpretation, the signified, e.g. a concept whose meaning the interpreter attempts to decode. In English, “information” is an uncountable mass noun. In information theory, information is taken as an ordered sequence of symbols from an alphabet, say an input alphabet χ, an output alphabet ϒ.
Information processing consists of an input-output function that maps any input sequence from χ into an output sequence from ϒ. The mapping may be deterministic, it may be memoryless. Information can be viewed as a type of input to an organism or system. Inputs are of two kinds. In his book Sensory Ecology Dusenbery called these causal inputs. Other inputs are important only because they are associated with causal inputs and can be used to predict the occurrence of a causal input at a time; some information is important because of association with other information but there must be a connection to a causal input. In practice, information is carried by weak stimuli that must be detected by specialized sensory systems and amplified by energy inputs before they can be functional to the organism or system. For example, light is a causal input to plants but for animals it only provides information; the colored light reflected from a flower is too weak to do much photosynthetic work but the visual system of the bee detects it and the bee's nervous system uses the information to guide the bee to the flower, where the bee finds nectar or pollen, which are causal inputs, serving a nutritional function.
The cognitive scientist and applied mathematician Ronaldo Vigo argues that information is a concept that requires at least two related entities to make quantitative sense. These are, any dimensionally defined category of objects S, any of its subsets R. R, in essence, is a representation of S, or, in other words, conveys representational information about S. Vigo defines the amount of information that R conveys a
United States Department of Defense
The Department of Defense is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government concerned directly with national security and the United States Armed Forces. The department is the largest employer in the world, with nearly 1.3 million active duty servicemen and women as of 2016. Adding to its employees are over 826,000 National Guardsmen and Reservists from the four services, over 732,000 civilians bringing the total to over 2.8 million employees. Headquartered at the Pentagon in Arlington, just outside Washington, D. C. the DoD's stated mission is to provide "the military forces needed to deter war and ensure our nation's security". The Department of Defense is headed by the Secretary of Defense, a cabinet-level head who reports directly to the President of the United States. Beneath the Department of Defense are three subordinate military departments: the United States Department of the Army, the United States Department of the Navy, the United States Department of the Air Force.
In addition, four national intelligence services are subordinate to the Department of Defense: the Defense Intelligence Agency, the National Security Agency, the National Geospatial-Intelligence Agency, the National Reconnaissance Office. Other Defense Agencies include the Defense Advanced Research Projects Agency, the Defense Logistics Agency, the Missile Defense Agency, the Defense Health Agency, Defense Threat Reduction Agency, the Defense Security Service, the Pentagon Force Protection Agency, all of which are under the command of the Secretary of Defense. Additionally, the Defense Contract Management Agency provides acquisition insight that matters, by delivering actionable acquisition intelligence from factory floor to the warfighter. Military operations are managed by ten functional Unified combatant commands; the Department of Defense operates several joint services schools, including the Eisenhower School and the National War College. The history of the defense of the United States started with the Continental Congress in 1775.
The creation of the United States Army was enacted on 14 June 1775. This coincides with the American holiday Flag Day; the Second Continental Congress would charter the United States Navy, on 13 October 1775, create the United States Marine Corps on 10 November 1775. The Preamble of the United States Constitution gave the authority to the federal government to defend its citizens: We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America. Upon the seating of the first Congress on 4 March 1789, legislation to create a military defense force stagnated as they focused on other concerns relevant to setting up the new government. President George Washington went to Congress to remind them of their duty to establish a military twice during this time.
On the last day of the session, 29 September 1789, Congress created the War Department, historic forerunner of the Department of Defense. The War Department handled naval affairs until Congress created the Navy Department in 1798; the secretaries of each of these departments reported directly to the president as cabinet-level advisors until 1949, when all military departments became subordinate to the Secretary of Defense. After the end of World War II, President Harry Truman proposed creation of a unified department of national defense. In a special message to Congress on 19 December 1945, the President cited both wasteful military spending and inter-departmental conflicts. Deliberations in Congress went on for months focusing on the role of the military in society and the threat of granting too much military power to the executive. On 26 July 1947, Truman signed the National Security Act of 1947, which set up a unified military command known as the "National Military Establishment", as well as creating the Central Intelligence Agency, the National Security Council, National Security Resources Board, United States Air Force and the Joint Chiefs of Staff.
The act placed the National Military Establishment under the control of a single Secretary of Defense. The National Military Establishment formally began operations on 18 September, the day after the Senate confirmed James V. Forrestal as the first Secretary of Defense; the National Military Establishment was renamed the "Department of Defense" on 10 August 1949 and absorbed the three cabinet-level military departments, in an amendment to the original 1947 law. Under the Department of Defense Reorganization Act of 1958, channels of authority within the department were streamlined, while still maintaining the ordinary authority of the Military Departments to organize and equip their associated forces; the Act clarified the overall decision-making authority of the Secretary of Defense with respect to these subordinate Military Departments and more defined the operational chain of command over U. S. military forces as running from the president to the Secretary of Defense and to the unified combatant commanders.
Provided in this legislation was a centralized research authority, the Advanced Research Projects Agency known as DARPA. The act was written and promoted by the Eisenhower administration, was signed into law 6 August 1958; the Secretary of Defense, appointed by the president with the advice and consent of the Senate, is by federal law (1
Telecommunication is the transmission of signs, messages, writings and sounds or information of any nature by wire, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology, it is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. Such transmission paths are divided into communication channels which afford the advantages of multiplexing. Since the Latin term communicatio is considered the social process of information exchange, the term telecommunications is used in its plural form because it involves many different technologies. Early means of communicating over a distance included visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, optical heliographs. Other examples of pre-modern long-distance communication included audio messages such as coded drumbeats, lung-blown horns, loud whistles. 20th- and 21st-century technologies for long-distance communication involve electrical and electromagnetic technologies, such as telegraph and teleprinter, radio, microwave transmission, fiber optics, communications satellites.
A revolution in wireless communication began in the first decade of the 20th century with the pioneering developments in radio communications by Guglielmo Marconi, who won the Nobel Prize in Physics in 1909, other notable pioneering inventors and developers in the field of electrical and electronic telecommunications. These included Charles Wheatstone and Samuel Morse, Alexander Graham Bell, Edwin Armstrong and Lee de Forest, as well as Vladimir K. Zworykin, John Logie Baird and Philo Farnsworth; the word telecommunication is a compound of the Greek prefix tele, meaning distant, far off, or afar, the Latin communicare, meaning to share. Its modern use is adapted from the French, because its written use was recorded in 1904 by the French engineer and novelist Édouard Estaunié. Communication was first used as an English word in the late 14th century, it comes from Old French comunicacion, from Latin communicationem, noun of action from past participle stem of communicare "to share, divide out.
Homing pigeons have been used throughout history by different cultures. Pigeon post had Persian roots, was used by the Romans to aid their military. Frontinus said; the Greeks conveyed the names of the victors at the Olympic Games to various cities using homing pigeons. In the early 19th century, the Dutch government used the system in Sumatra, and in 1849, Paul Julius Reuter started a pigeon service to fly stock prices between Aachen and Brussels, a service that operated for a year until the gap in the telegraph link was closed. In the Middle Ages, chains of beacons were used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could only pass a single bit of information, so the meaning of the message such as "the enemy has been sighted" had to be agreed upon in advance. One notable instance of their use was during the Spanish Armada, when a beacon chain relayed a signal from Plymouth to London. In 1792, Claude Chappe, a French engineer, built the first fixed visual telegraphy system between Lille and Paris.
However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres. As a result of competition from the electrical telegraph, the last commercial line was abandoned in 1880. On 25 July 1837 the first commercial electrical telegraph was demonstrated by English inventor Sir William Fothergill Cooke, English scientist Sir Charles Wheatstone. Both inventors viewed their device as "an improvement to the electromagnetic telegraph" not as a new device. Samuel Morse independently developed a version of the electrical telegraph that he unsuccessfully demonstrated on 2 September 1837, his code was an important advance over Wheatstone's signaling method. The first transatlantic telegraph cable was completed on 27 July 1866, allowing transatlantic telecommunication for the first time; the conventional telephone was invented independently by Alexander Bell and Elisha Gray in 1876. Antonio Meucci invented the first device that allowed the electrical transmission of voice over a line in 1849.
However Meucci's device was of little practical value because it relied upon the electrophonic effect and thus required users to place the receiver in their mouth to "hear" what was being said. The first commercial telephone services were set-up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London. Starting in 1894, Italian inventor Guglielmo Marconi began developing a wireless communication using the newly discovered phenomenon of radio waves, showing by 1901 that they could be transmitted across the Atlantic Ocean; this was the start of wireless telegraphy by radio. Voice and music had little early success. World War I accelerated the development of radio for military communications. After the war, commercial radio AM broadcasting began in the 1920s and became an important mass medium for entertainment and news. World War II again accelerated development of radio for the wartime purposes of aircraft and land communication, radio navigation and radar. Development of stereo FM broadcasting of radio
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