A computer network is a system in which a number of independent computers are linked together to share data and peripherals, such as hard disks and printers.
Three advantages of using a computer network are the ability to share information (or data), to share hardware and software, and to centralize administration and support.
The most basic version of a LAN is two computers that are connected by a cable. An example of a more complex LAN is hundreds of connected computers and peripherals scattered throughout a large organization, such as a municipality. In both cases, the LAN is confined to a limited geographic area.
Because a WAN has no geographical limitations, it can connect computers and other devices in separate cities or on opposite sides of the world. A multinational corporation with linked computers in different countries is using a WAN. Probably the ultimate WAN is the Internet.