For example, suppose a network consisting of four personal computers, and that each of them can be client and/or server of the other three. It is not usual that a network peer to peer there is an administrator of the network, but that usually every PC user who doing the functions of administrator, decide that share resources and which are not. Depending on the distance that separates the teams that make up a network, this can be of two types: local area or wide area. Network Local area and wide area in a (Local Area Network LAN) local area network the computers are connected within walking distance. She may belong, for example, all computers in an Office, a classroom or a supermarket.
In all cases, the configuration of computers may be client/server or peer to peer. The geographic boundary of a LAN is a few kilometers, so that could also be part of it, for example, all computers on a University campus, a hospital or an airport. But when the distances between the teams are larger (tens, hundreds or thousands of miles away), the network changes its name Wan (Wide Area Network WAN). For example, the network that connect to computers in a company that has offices in several cities or countries is a WAN. On the other hand, a WAN can also connect to two or more LANs. For example, the company that has offices in different cities, normal is to install a LAN in each Office and interconnect them forming a WAN.