There are many components for a communication network. The basic three components are a host computer, a client, and a circuit. Besides these components, others include front-end processors, teleprocessing software, input terminals, and specialists.

Host Computer (Server)

The host computer or server (a mainframe, minicomputer, or microcomputer) is the main unit in the communication network. It stores data and programs that can be accessed by the clients. The host computer is responsible for performing the data processing tasks of the network. After processing has occurred, the data or information is routed back to a front-end processor. In distributed processing or client-server computing, several host computers may be tied together by the data communication network.

The circuit is a communication channel that allows the data and information to move through the pathway. It includes several types of lines, such as twisted wires, coaxial cables, and fiber optic cables. It also contains wireless transmission circuits such as microwaves and satellites, and it is becoming more popular.