The Local Area Network (LAN) is by far the most common type of data network. As the name suggests, a LAN serves a local area (typically the area of a floor of a building, but in some cases spanning a distance of several kilometers). Typical installations are in industrial plants, office buildings, college or university campuses, or similar locations. In these locations, it is feasible for the owning Organisation to install high quality, high-speed communication links interconnecting nodes. Typical data transmission speeds are one to 100 megabits per second.
A wide variety of LANs have been built and installed, but a few types have more recently become dominant. The most widely used LAN system is the Ethernet system developed by the Xerox Corporation.
Intermediate nodes (i.e. repeaters, bridges and switches) allow LANs to be connected together to form larger LANs. A LAN may also be connected to another LAN or to WANs using a "router".
In summary, a LAN is a communications network which is:
LANs allow users to share resources on computers within an organisation, and may be used to provide a (shared) access to remote organisations through a router connected to a Wide Area Network (WAN).
http://www.erg.abdn.ac.uk/users/gorry Date: 10/11/1995 Revised: 7/10/2003