The term channel refers to a communications path between two computers or devices, such as fax machines. A channel can be physical, such as the wires or other materials that connect the two units. For personal computers, a channel is the same as an expansion bus--the collection of wires and protocols that permits the insertion of circuit boards to expand the performance of the computer.

A channel functions to provide a direct or more indirect, switched point-to-point connection. The latter are manifest as networks. The advent of networks, with both their volume and the high speed of information, has necessitated the development of other forms of channels. Fibre channels were developed, for example. Fibre channels provide a serial link between computers, ranging from supercomputers to desktop personal computers to peripheral devices. High-speed Internet hookups that utilize cables are a type of fiber connection.