In computer-based LANs, at least two intelligent systems needing to share Data are required. These intelligent systems, when connected to the network, are referred to as Nodes, and are able to communicate with each other via a Network Topology such as Star, Bus, Ring or Tree.

A Node usually consists of a personal computer, an adapter with a Cable and other adapters to the personal computer (such as: Disk drives, printers and plotters). In addition to the personal computer hardware, all necessary Software must be available.