Information Technology Tutorials - Your own free e-library on IT
Information technology (IT) is that the use of computers to store, retrieve, transmit, and manipulate knowledge, or data, oft within the reference of a business or alternative enterprise.
IT is considered to be a part of the information and communications technology (ICT). An information technology system (IT system) is commonly an information system, a communications system or, more particularly speaking, a computer system – including all of the hardware, software, and peripheral equipment – operated by user groups.
Humans are gathering, 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 during a 1958 article printed within the Harvard Business Review; authors Harold J. Leavitt and Thomas L. Whisler mentioned that "the new technology does not yet have a single established name.
We shall call it data technology (IT)." This definition consists of 03 categories: process techniques, the application of statistical and mathematical methods in decision-making, and the simulation of higher-order
thinking through computer software.
The term is usually referred to as a synonym for computers and computer networks, but it also includes other information dispersing technologies such as television and telephones. Several product or services inside AN economy square measure related to data technology, as well as constituent, software, electronics, semiconductors, internet, telecom equipment, and e-commerce.
Early electronic computers like Colossus created use of punched tape, a protracted strip of paper on that knowledge was painted by a series of holes, a technology now written-off.
The electronic data repository, 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 primary utilization of that was the mercury electrical circuit.
The first random-access digital memory 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 endlessly rested, and therefore 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, the world's first commercially available general-purpose electronic computer. IBM introduced the primary disk drive in 1956, as a component of their 305 RAMAC computer system.
Most electronic data today is still stored magnetically on hard disks, or optically on media such as CD-ROMs. Until 2002 most of the information was stored on analog devices, but that year e storage capacity exceeded analog for the first time. As of 2007 almost 94% of the data stored globally was held digitally: 52% on hard disks, 28% on optical devices and 11% on digital magnetic tape.
It has been speculated that the worldwide capability to store data on electronic devices grew from but three exabytes in 1986 to 295 exabytes in 2007, doubling roughly every 3 years.
Database management systems appeared in the 1960s to address the problem of storing and retrieving huge amounts of data correctly and fast. One of the earliest such systems was IBM's Information Management System (IMS), which is till date widely deployed more than 50 years later.
IMS stores knowledge 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 the Oracle organization in 1981.
All direction systems comprise of a variety of parts that along allow the info they store to be accessed at the same time by giant users whereas maintaining its integrity.
A characteristic of all databases is that the structure of the data they comprise is defined and stored separately from the data itself, in a database schema.
The extensible markup language (XML) has become a commonformat for data representation in these years.
Although XML knowledge may be kept in usual file systems, it is commonly held in relational databases to take advantage of their "solid implementation checked by years of both the theoretical and practical effort".
As AN evolution of the quality Generalized nomenclature (SGML), XML's text-based structure provides the advantage of being each machine and human-readable.