: Data 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,

: Databases

Database management systems emerged in the 1960s to address the problem of storing and retrieving large amounts of data accurately and quickly.

: Data retrieval

The relational database model introduced a programming-language independent Structured Query Language (SQL), based on relational algebra.

: Data transmission

Data transmission has three aspects: transmission, propagation, and reception.[33] It can be broadly categorized as broadcasting,

Information technology

Information technology (IT) is the application of computers to store, retrieve, transmit and manipulate data,[1] often in the context of a business or other enterprise.[2] IT is considered a subset of information and communications technology (ICT)

History of computer technology

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.