Computer Network

Computer network simply referred to as a network, is a group of computers and devices interconnected by communications channels. Network facilitates communications among users and allows users to divide resources.

History

Premature networks of communicating computers incorporated the military radar system Semi-Automatic Ground Environment and its relative the commercial airline reservation system Semi-Automatic Business Research Environment, started in the late 1950.

The Advanced Research Projects Agency started funding the design of the Advanced Research Projects Agency Network (ARPANET) for the United States Department of Defense in the 1960. The ARPANET evolved into the modern Internet.

Purpose

Computer networks can be used for a multiplicity of purposes:

            1. Make easy communications. Using a network, people can communicate proficiently and easily by email, instant messaging, video conference, video telephone calls, telephone and chat rooms.

2. Allotment resource. Each computer on a network may access and use hardware resources on the network, such as printing a document on a shared network printer in a networked environment.

3. Distribution files, data, and information. Authorized user may access data and information stored on another computer on the network. The potential of providing access to data and information on shared storage devices is an important feature of many networks.

           

4. Sharing software. Users may run application programs on remote computers.

           

Network classification

Computer networks can be classified consistent with the hardware and software that is used to interconnect the individual devices in the network, such as optical fiber, Ethernet, wireless LAN, HomePNA.

Ethernet defined by IEEE 802 develop various standards and mediums that enable communication between devices. By the devices of hubs, switches, bridges, or routers. Wireless LAN technology is designed to connect through the devices without wiring. These devices use radio waves or infrared signals as a transmission medium. ITU-T G.hn technology uses existing home wiring (coaxial cable, phone lines and power lines) to create a high-speed (up to 1 Gigabit/s) local area network.