Data Communication is the term that is used when describing how a number of desktop computers can access information from a source external to the system they are using. Data Communication comes into this, as this is the way that the computers connect to the external source. Most computers connect by using a Modem, although there are many different ways. On this site I have mentioned three of the main ways of connection, Modem, ADSL and ISDN, although there are many other ways such as Satellite Link-Up, which is much less used in today’s society.

Data Communications work on two types of networks, a Local Area Network (LAN) or a Wide Area Network (WAN).

A LAN system is generally a networking system that has been set up in one building such as an office block or a college/university, and lets users access a small number of hard discs which allows them to share work and view other peoples work. This has a major advantage in that data transferring is quick and easy. It is also a cheaper alternative as it means that many users on the same system can access the same peripherals such as printer and scanner instead of one being bought for each client computer.

A WAN system is a system that is connected over a large area, from a couple of miles over a city to thousands of miles to a different country. It usually consists of a multitude of LAN systems and can be extremely large. This is where Data Communications becomes important, as this is how a client can connect to the WAN system. The biggest WAN system in existence is the Internet and Data Communications are important as having a better system allows the transfer of data to be much faster.