- A system of computers, transmission channels, and related resources which are interconnected to exchange information. A communications network may be comparatively small, in which case it can be a LAN, or relatively large, in which case it could be a WAN. A LAN may be confined, for instance, to a single building, while a WAN may cover an entire country. The communications channels in a network may be temporary or permanent. Also called network (1), or communications network.