A geographically limited communication network that connects users within a defined area. A LAN is generally contained within a building or small group of buildings and is managed and owned by a single enterprise. The shorter distances within a building or campus enable faster communications at a lower cost than wide-area networks (WANs). Although an increasing number of LANs use Internet standards and protocols, they are normally protected from the public Internet by firewalls.

LANs are generally used to perform the following functions:

• Send output to printers attached to the network.

• Transfer data or software to or from other systems attached to the network.

• Send e-mail to other users on the network.

• Access wider-area networks, including the Internet, via a direct connection from the network, for external file transfer, e-mail, facsimile, group collaboration and videoconferencing.