Any number of computers (e.g., PCs and servers) and devices (e.g., printers and modems) joined together by a physical communications link. In the enterprise context, networks allow information to be passed between computers, irrespective of where those computers are located. Networks provide the roads for information traffic (e.g., sending files and e-mail) within a corporate environment, and allow users to access databases and share applications residing on servers. If a network does not go outside of a company building, or campus, then it is known as a local-area network (LAN). If it has a bridge to other outside networks, usually via lines owned by public telecommunications carriers like AT&T, then it is known as a wide-area network (WAN).