Information technology (IT) is the use of computers to store, retrieve, transmit, and manipulate data, or information, often in the context of a business or other enterprise. IT is considered to be a subset of information and communications technology (ICT). An information technology system (IT system) is generally an information system, a communications system or, more specifically speaking, a computer system – including all hardware, software and peripheral equipment – operated by a limited group of users.
Humans have been storing, retrieving, manipulating, and communicating information since the Sumerians in Mesopotamia developed writing in about 3000 BC, but the term information technology in its modern sense first appeared in a 1958 article published in the Harvard Business Review; authors Harold J. Leavitt and Thomas L. Whisler commented that "the new technology does not yet have a single established name. We shall call it information technology (IT)." Their definition consists of three categories: techniques for processing, the application of statistical and mathematical methods to decision-making, and the simulation of higher-order thinking through computer programs.
The term is commonly used as a synonym for computers and computer networks, but it also encompasses other information distribution technologies such as television and telephones. Several products or services within an economy are associated with information technology, including computer hardware, software, electronics, semiconductors, internet, telecom equipment, and e-commerce.[a]
Based on the storage and processing technologies employed, it is possible to distinguish four distinct phases of IT development: pre-mechanical (3000 BC – 1450 AD), mechanical (1450–1840), electromechanical (1840–1940), and electronic (1940–present). This article focuses on the most recent period (electronic), which began in about 1940.
Devices have been used to aid computation for thousands of years, probably initially in the form of a tally stick. The Antikythera mechanism, dating from about the beginning of the first century BC, is generally considered to be the earliest known mechanical analog computer, and the earliest known geared mechanism. Comparable geared devices did not emerge in Europe until the 16th century, and it was not until 1645 that the first mechanical calculator capable of performing the four basic arithmetical operations was developed.
Electronic computers, using either relays or valves, began to appear in the early 1940s. The electromechanical Zuse Z3, completed in 1941, was the world's first programmable computer, and by modern standards one of the first machines that could be considered a complete computing machine. Colossus, developed during the Second World War to decrypt German messages, was the first electronic digital computer. Although it was programmable, it was not general-purpose, being designed to perform only a single task. It also lacked the ability to store its program in memory; programming was carried out using plugs and switches to alter the internal wiring. The first recognisably modern electronic digital stored-program computer was the Manchester Baby, which ran its first program on 21 June 1948.
The development of transistors in the late 1940s at Bell Laboratories allowed a new generation of computers to be designed with greatly reduced power consumption. The first commercially available stored-program computer, the Ferranti Mark I, contained 4050 valves and had a power consumption of 25 kilowatts. By comparison the first transistorised computer, developed at the University of Manchester and operational by November 1953, consumed only 150 watts in its final version.
Early electronic computers such as Colossus made use of punched tape, a long strip of paper on which data was represented by a series of holes, a technology now obsolete. Electronic data storage, which is used in modern computers, dates from World War II, when a form of delay line memory was developed to remove the clutter from radar signals, the first practical application of which was the mercury delay line. The first random-access digital storage device was the Williams tube, based on a standard cathode ray tube, but the information stored in it and delay line memory was volatile in that it had to be continuously refreshed, and thus was lost once power was removed. The earliest form of non-volatile computer storage was the magnetic drum, invented in 1932 and used in the Ferranti Mark 1, the world's first commercially available general-purpose electronic computer.
IBM introduced the first hard disk drive in 1956, as a component of their 305 RAMAC computer system.:6 Most digital data today is still stored magnetically on hard disks, or optically on media such as CD-ROMs.:4–5 Until 2002 most information was stored on analog devices, but that year digital storage capacity exceeded analog for the first time. As of 2007 almost 94% of the data stored worldwide was held digitally: 52% on hard disks, 28% on optical devices and 11% on digital magnetic tape. It has been estimated that the worldwide capacity to store information on electronic devices grew from less than 3 exabytes in 1986 to 295 exabytes in 2007, doubling roughly every 3 years.
Database management systems emerged in the 1960s to address the problem of storing and retrieving large amounts of data accurately and quickly. One of the earliest such systems was IBM's Information Management System (IMS), which is still widely deployed more than 50 years later. IMS stores data hierarchically, but in the 1970s Ted Codd proposed an alternative relational storage model based on set theory and predicate logic and the familiar concepts of tables, rows and columns. The first commercially available relational database management system (RDBMS) was available from Oracle in 1981.
All database management systems consist of a number of components that together allow the data they store to be accessed simultaneously by many users while maintaining its integrity. A characteristic of all databases is that the structure of the data they contain is defined and stored separately from the data itself, in a database schema.
The extensible markup language (XML) has become a popular format for data representation in recent years. Although XML data can be stored in normal file systems, it is commonly held in relational databases to take advantage of their "robust implementation verified by years of both theoretical and practical effort". As an evolution of the Standard Generalized Markup Language (SGML), XML's text-based structure offers the advantage of being both machine and human-readable.
The terms "data" and "information" are not synonymous. Anything stored is data, but it only becomes information when it is organized and presented meaningfully.:1–9 Most of the world's digital data is unstructured, and stored in a variety of different physical formats[b] even within a single organization. Data warehouses began to be developed in the 1980s to integrate these disparate stores. They typically contain data extracted from various sources, including external sources such as the Internet, organized in such a way as to facilitate decision support systems (DSS).:4–6
Data transmission has three aspects: transmission, propagation, and reception. It can be broadly categorized as broadcasting, in which information is transmitted unidirectionally downstream, or telecommunications, with bidirectional upstream and downstream channels.
XML has been increasingly employed as a means of data interchange since the early 2000s, particularly for machine-oriented interactions such as those involved in web-oriented protocols such as SOAP, describing "data-in-transit rather than ... data-at-rest". One of the challenges of such usage is converting data from relational databases into XML Document Object Model (DOM) structures.:228–31
Hilbert and Lopez identify the exponential pace of technological change (a kind of Moore's law): machines' application-specific capacity to compute information per capita roughly doubled every 14 months between 1986 and 2007; the per capita capacity of the world's general-purpose computers doubled every 18 months during the same two decades; the global telecommunication capacity per capita doubled every 34 months; the world's storage capacity per capita required roughly 40 months to double (every 3 years); and per capita broadcast information has doubled every 12.3 years.
Massive amounts of data are stored worldwide every day, but unless it can be analysed and presented effectively it essentially resides in what have been called data tombs: "data archives that are seldom visited". To address that issue, the field of data mining – "the process of discovering interesting patterns and knowledge from large amounts of data" – emerged in the late 1980s.
In an academic context, the Association for Computing Machinery defines IT as "undergraduate degree programs that prepare students to meet the computer technology needs of business, government, healthcare, schools, and other kinds of organizations .... IT specialists assume responsibility for selecting hardware and software products appropriate for an organization, integrating those products with organizational needs and infrastructure, and installing, customizing, and maintaining those applications for the organization’s computer users."
In a business context, the Information Technology Association of America has defined information technology as "the study, design, development, application, implementation, support or management of computer-based information systems". The responsibilities of those working in the field include network administration, software development and installation, and the planning and management of an organization's technology life cycle, by which hardware and software are maintained, upgraded and replaced.
The business value of information technology lies in the automation of business processes, provision of information for decision making, connecting businesses with their customers, and the provision of productivity tools to increase efficiency.
Commonly a synonym for computers and computer networks but more broadly designating any technology that is used to generate, store, process, and/or distribute information electronically, including television and telephone.
Accenture is a global management consulting and professional services firm that provides strategy, consulting, digital, technology and operations services. A Fortune Global 500 company, it has been incorporated in Dublin, Ireland, since 1 September 2009. In 2018, the company reported net revenues of $39.6 billion, with more than 459,000 employees serving clients in more than 200 cities in 120 countries. In 2015, the company had about 150,000 employees in India, about 48,000 in the US, and about 50,000 in the Philippines. Accenture's current clients include 95 of the Fortune Global 100 and more than three-quarters of the Fortune Global 500.Data structure
In computer science, a data structure is a data organization, management and storage format that enables efficient access and modification. More precisely, a data structure is a collection of data values, the relationships among them, and the functions or operations that can be applied to the data.Geographic information system
A geographic information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data. GIS applications are tools that allow users to create interactive queries (user-created searches), analyze spatial information, edit data in maps, and present the results of all these operations. GIS (more commonly GIScience) sometimes refers to geographic information science (GIScience), the science underlying geographic concepts, applications, and systems.GIS can refer to a number of different technologies, processes, techniques and methods. It is attached to many operations and has many applications related to engineering, planning, management, transport/logistics, insurance, telecommunications, and business. For that reason, GIS and location intelligence applications can be the foundation for many location-enabled services that rely on analysis and visualization.
GIS can relate unrelated information by using location as the key index variable. Locations or extents in the Earth space–time may be recorded as dates/times of occurrence, and x, y, and z coordinates representing, longitude, latitude, and elevation, respectively. All Earth-based spatial–temporal location and extent references should be relatable to one another and ultimately to a "real" physical location or extent. This key characteristic of GIS has begun to open new avenues of scientific inquiry.IT service management
IT service management (ITSM) refers to the entirety of activities – directed by policies, organized and structured in processes and supporting procedures – that are performed by an organization to design, plan, deliver, operate and control information technology (IT) services offered to customers.Differing from more technology-oriented IT management approaches like network management and IT systems management, IT service management is characterized by adopting a process approach towards management, focusing on customer needs and IT services for customers rather than IT systems, and stressing continual improvement. The CIO WaterCoolers' annual ITSM report states that business use ITSM "mostly in support of customer experience (35%) and service quality (48%)."Indian Institute of Information Technology, Design and Manufacturing, Kancheepuram
Indian Institute of Information Technology, Design and Manufacturing, Kancheepuram (IIITDM Kancheepuram, also IIITD&M Kancheepuram) is an Institute of National Importance established in 2007 by the Ministry of Human Resource Development, Government of India to pursue design and manufacturing oriented engineering education, research and to promote the competitive advantage of Indian products in global markets. It was declared as an Institute of National Importance (INI) by the Ministry of Human Resource Development, Government of India, in July 2011, thus becoming the first IIIT to be accorded this status. Later in 2014, IIIT Bill 2014 was passed by the Parliament on 1 December 2014, thus granting the status of Institutes of National Importance upon the 5 MHRD funded IIITs including IIITDM Kancheepuram. Previously IIITDM Kancheepuram was mentoring IIITDM Kurnool in its new campus at Chennai.Indian Institute of Information Technology Tiruchirappalli
Indian Institute of Information Technology Tiruchirappalli (IIITT) is a higher education academic and research institute located in Tiruchirappalli, Tamil Nadu, India. It is one of the Indian Institutes of Information Technology (IIITs) established under the non-profit Public-Private Partnership and is an funded by the Government of India, Government of Tamil Nadu and the Indian industry partners in the ratio of 50:35:15. Industry partners include Tata Consultancy Services (TCS), Cognizant Technology Solutions (CTS), Infosys, Ramco Systems, ELCOT, and Navitas (Take Solutions). Together with the other IIITs, it has been granted the status of Institute of National importance in 2017.Information Technology Act, 2000
The Information Technology Act, 2000 (also known as ITA-2000, or the IT Act) is an Act of the Indian Parliament (No 21 of 2000) notified on 17 October 2000. It is the primary law in India dealing with cybercrime and electronic commerce. It is based on the United Nations Model Law on Electronic Commerce 1996 (UNCITRAL Model) recommended by the General Assembly of United Nations by a resolution dated 30 January 1997.Information and communications technology
Information and communications technology (ICT) is an extensional term for information technology (IT) that stresses the role of unified communications and the integration of telecommunications (telephone lines and wireless signals) and computers, as well as necessary enterprise software, middleware, storage, and audiovisual systems, that enable users to access, store, transmit, and manipulate information.The term ICT is also used to refer to the convergence of audiovisual and telephone networks with computer networks through a single cabling or link system. There are large economic incentives (huge cost savings due to the elimination of the telephone network) to merge the telephone network with the computer network system using a single unified system of cabling, signal distribution, and management.
ICT is a broad subject and the concepts are evolving. It covers any product that will store, retrieve, manipulate, transmit, or receive information electronically in a digital form (e.g., personal computers, digital television, email, or robots). For clarity, Zuppo provided an ICT hierarchy where all levels of the hierarchy "contain some degree of commonality in that they are related to technologies that facilitate the transfer of information and various types of electronically mediated communications". Theoretical differences between interpersonal-communication technologies and mass-communication technologies have been identified by the philosopher Piyush Mathur. Skills Framework for the Information Age is one of many models for describing and managing competencies for ICT professionals for the 21st century.Information technology consulting
In management, information technology consulting (also called IT consulting, computer consultancy, business and technology services, computing consultancy, technology consulting, and IT advisory) as a field of activity focuses on advising organizations on how best to use information technology (IT) in achieving their business objectives.Information technology in India
Information Technology in India is an industry consisting of two major components: IT services and business process outsourcing (BPO). The sector has increased its contribution to India's GDP from 1.2% in 1998 to 7.7% in 2017. According to NASSCOM, the sector aggregated revenues of US$160 billion in 2017, with export revenue standing at US$99 billion and domestic revenue at US$48 billion, growing by over 13%. The United States accounts for two-thirds of India's IT services exports.Infosys
Infosys Limited (formerly Infosys Technologies Limited) is an Indian multinational corporation that provides business consulting, information technology and outsourcing services. It has its headquarters in Bengaluru, Karnataka, India.Infosys is the second-largest Indian IT company by 2017 revenues and 596th largest public company in the world based on revenue. On September 28, 2018, its market capitalisation was $44.32 billion. The credit rating of the company is A− (rating by Standard & Poor's).Kriti Sanon
Kriti Sanon (born 27 July 1990) is an Indian actress who appears predominantly in Hindi films. Born and raised in New Delhi, she pursued an engineering degree from the Jaypee Institute of Information Technology, after which she briefly worked as a model. She made her acting debut with the Telugu psychological thriller 1: Nenokkadine (2014) and had her first Hindi film release in Sabbir Khan's action film Heropanti (2014), for which she won the Filmfare Award for Best Female Debut.
Sanon went on to play the lead female role in three commercially successful films, the action-comedy Dilwale (2015), which ranks among the highest-grossing Indian films of all time; and the romantic comedies Bareilly Ki Barfi (2017) and Luka Chuppi (2019).List of International Organization for Standardization standards
This is a list of published International Organization for Standardization (ISO) standards and other deliverables. For a complete and up-to-date list of all the ISO standards, see the ISO catalogue.The standards are protected by copyright and most of them must be purchased. However, about 300 of the standards produced by ISO and IEC's Joint Technical Committee 1 (JTC1) have been made freely and publicly available.List of the largest information technology companies
This is a list of the world's largest technology companies by revenue. The list shows technology companies ranked by annual revenue from their fiscal years ended on or before March 31, 2018, according to Fortune Global 500 magazine. Other metrics not shown here, in particular market capitalization, are often used alternatively to define the size of a company.
The list includes companies whose primary business activities are associated with technology industry which includes computer hardware, software, electronics, semiconductor, internet, telecom equipment, e-commerce and computer services. Note: This list shows only companies with annual revenues exceeding US$50 billion.Network packet
A network packet is a formatted unit of data carried by a packet-switched network. A packet consists of control information and user data, which is also known as the payload. Control information provides data for delivering the payload, for example: source and destination network addresses, error detection codes, and sequencing information. Typically, control information is found in packet headers and trailers.
In packet switching, the bandwidth of the communication medium is shared between multiple communication sessions, in contrast to circuit switching, in which circuits are preallocated for the duration of one session and data is typically transmitted as a continuous bit stream.Outsourcing
Outsourcing is an agreement in which one company hires another company to be responsible for a planned or existing activity that is or could be done internally.It often involves the contracting of a business process (e.g., payroll processing, claims processing), operational, and/or non-core functions, such as manufacturing, facility management, call center support). The term "outsourcing" came from "outside resourcing" and dates back to at least 1981. Outsourcing sometimes involves transferring employees and assets from one firm to another.
Outsourcing is also the practice of handing over control of public services to private enterprises.Outsourcing includes both foreign and domestic contracting, and sometimes includes offshoring (relocating a business function to a distant country) or nearshoring (transferring a business process to a nearby country).
Offshoring and outsourcing are not mutually inclusive: there can be one without the other. They can be intertwined (Offshore outsourcing), and can be individually or jointly, partially or completely reversed, involving terms such as reshoring, inshoring, and insourcing.Software developer
A software developer is a person concerned with facets of the software development process, including the research, design, programming, and testing of computer software. Other job titles which are often used with similar meanings are programmer, software analyst, and software engineer.
In a large company, there may be employees whose sole responsibility consists of only one of the phases above. In smaller development environments, a few people or even a single individual might handle the complete process.Tata Consultancy Services
Tata Consultancy Services Limited (TCS) is an Indian multinational information technology (IT) service, consulting company headquartered in Mumbai, Maharashtra. It is part of the Tata Group and operates in 46 countries.TCS is one of the largest Indian companies by market capitalization. TCS is now placed among the most valuable IT services brands worldwide. In 2015, TCS is ranked 64th overall in the Forbes World's Most Innovative Companies ranking, making it both the highest-ranked IT services company and the top Indian company. It is the world's 2nd largest IT services provider. As of 2017, it is ranked 10th on the Fortune India 500 list. In April 2018, TCS became the first Indian IT company to breach $100 billion market capitalization, and second Indian company ever (after Reliance Industries achieved it in 2007) after its m-cap stood at Rs 6,79,332.81 crore ($102.6 billion) in Bombay Stock Exchange.In 2016-2017, Parent company Tata Sons owned 70% of TCS; and more than 70% of Tata Sons' dividends were generated by TCS. In March 2018, Tata Sons decided to sell stocks of TCS worth $1.25 billion in a bulk deal.Wipro
Wipro Limited is an Indian multinational corporation that provides information technology, consulting and business process services. It is headquartered in Bengaluru, Karnataka, India.In 2013, Wipro demerged its non-IT businesses into separate companies.