Information technology (IT) is the use of computers to create, process, store, retrieve, and exchange all kinds of data and information. IT forms part 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 IT users.
Although humans have been storing, retrieving, manipulating, and communicating information since the earliest writing systems were developed, 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.
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), elector mechanical (1840—1940), and electronic (1940 to present).
Information technology is also a branch of computer science, which can be defined as the overall study of procedure, structure, and the processing of various types of data. As this field continues to evolve across the world, the overall priority and importance has also grown, which is where we begin to see the introduction of computer science-related courses in K-12 education.
Data processing
Storage
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, which was based on a standard cathode ray tube. However, the information stored in it and delay-line memory was volatile in the fact 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. Most digital data today is still stored magnetically on hard disks, or optically on media such as CD-ROMs. 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.
Databases
Database Management Systems (DMS) emerged in the 1960s to address the problem of storing and retrieving large amounts of data accurately and quickly. An early such system 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. In 1981, the first commercially available relational database management system (RDBMS) was released by Oracle.
All DMS consist of components, they allow the data they store to be accessed simultaneously by many users while maintaining its integrity. All databases are common in one point that the structure of the data they contain is defined and stored separately from the data itself, in a database schema.
In recent years, the extensible markup language (XML) has become a popular format for data representation. 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.
Transmission
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”.
Manipulation
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 analyzed 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.
Services
The technology and services it provides for sending and receiving electronic messages (called “letters” or “electronic letters”) over a distributed (including global) computer network. In terms of the composition of elements and the principle of operation, electronic mail practically repeats the system of regular (paper) mail, borrowing both terms (mail, letter, envelope, attachment, box, delivery, and others) and characteristic features — ease of use, message transmission delays, sufficient reliability and at the same time no guarantee of delivery. The advantages of e-mail are: easily perceived and remembered by a person addresses of the form user_name@domain_name (for example, somebody@example.com); the ability to transfer both plain text and formatted, as well as arbitrary files; independence of servers (in the general case, they address each other directly); sufficiently high reliability of message delivery; ease of use by humans and programs.
Disadvantages of e-mail: the presence of such a phenomenon as spam (massive advertising and viral mailings); the theoretical impossibility of guaranteed delivery of a particular letter; possible delays in message delivery (up to several days); limits on the size of one message and on the total size of messages in the mailbox (personal for users).
Search system
A software and hardware complex with a web interface that provides the ability to search for information on the Internet. A search engine usually means a site that hosts the interface (front-end) of the system. The software part of a search engine is a search engine (search engine) — a set of programs that provides the functionality of a search engine and is usually a trade secret of the search engine developer company. Most search engines look for information on World Wide Web sites, but there are also systems that can look for files on FTP servers, items in online stores, and information on Usenet newsgroups. Improving search is one of the priorities of the modern Internet (see the Deep Web article about the main problems in the work of search engines).
Commercial effects
Companies in the information technology field are often discussed as a group as the “tech sector” or the “tech industry.” These titles can be misleading at times and should not be mistaken for “tech companies;” which are generally large scale, for-profit corporations that sell consumer technology and software. It is also worth noting that from a business perspective, Information Technology departments are a “cost center” the majority of the time. A cost center is a department or staff which incurs expenses, or “costs,” within a company rather than generating profits or revenue streams. Modern businesses rely heavily on technology for their day-to-day operations, so the expenses delegated to cover technology that facilitates business in a more efficient manner are usually seen as “just the cost of doing business.” IT departments are allocated funds by senior leadership and must attempt to achieve the desired deliverables while staying within that budget. Government and the private sector might have different funding mechanisms, but the principles are more-or-less the same. This is an often overlooked reason for the rapid interest in automation and Artificial Intelligence, but the constant pressure to do more with less is opening the door for automation to take control of at least some minor operations in large companies.
Many companies now have IT departments for managing the computers, networks, and other technical areas of their businesses. Companies have also sought to integrate IT with business outcomes and decision-making through a Biz Ops or business operations department.
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.
Information services
Information services is a term somewhat loosely applied to a variety of IT-related services offered by commercial companies, as well as data brokers.
- U.S. Employment distribution of computer systems design and related services, 2011
- U.S. Employment in the computer systems and design related services industry, in thousands, 1990-2011
- U.S. Occupational growth and wages in computer systems design and related services, 2010-2020
- U.S. projected percent change in employment in selected occupations in computer systems design and related services, 2010-2020
- U.S. projected average annual percent change in output and employment in selected industries, 2010-2020
Ethics
The field of information ethics was established by mathematician Norbert Wiener in the 1940s. Some of the ethical issues associated with the use of information technology include:
- Breaches of copyright by those downloading files stored without the permission of the copyright holders
- Employers monitoring their employees’ emails and other Internet usage
- Unsolicited emails
- Hackers accessing online databases
- Web sites installing cookies or spyware to monitor a user’s online activities, which may be used by data brokers

