Information technology (
IT) is the application of
computers and
telecommunications equipment to store, retrieve, transmit and manipulate data,
[1] often in the context of a business or other enterprise.
[2]
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
industries are associated with information technology, such as
computer hardware,
software,
electronics,
semiconductors,
internet,
telecom equipment,
e-commerce and
computer services.
[3][4]
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 organisation's technology life cycle, by which
hardware and software is maintained, upgraded, and replaced.
Humans have been storing, retrieving, manipulating and communicating information since the
Sumerians in
Mesopotamia developed
writing in about 3000 BC,
[6] 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)."
[7]
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).
[6] This article focuses on the most recent period (electronic), which began in about 1940.
History of computers
Devices have been used to aid computation for thousands of years, probably initially in the form of a
tally stick.
[8] The
Antikythera mechanism, dating from about the beginning of the first century BC, is generally considered to be the earliest known mechanical
analog computer; it is also 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.
Instead, 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 Small-Scale Experimental Machine (SSEM), which ran its first program on 21 June 1948.
[13]
source - here
