What is a WAN?

A WAN is a data communications network that operates beyond the geographic scope of a LAN.

WANs are different from LANs in several ways. While a LAN connects computers, peripherals, and other devices in a single building or other small geographic area, a WAN allows the transmission of data across greater geographic distances. In addition, an enterprise must subscribe to a WAN service provider to use WAN carrier network services. LANs are typically owned by the company or organization that uses them.

WANs use facilities provided by a service provider, or carrier, such as a telephone or cable company, to connect the locations of an organization to each other, to locations of other organizations, to external services, and to remote users. WANs generally carry a variety of traffic types, such as voice, data, and video.

Here are the three major characteristics of WANs:

WANs generally connect devices that are separated by a broader geographical area than can be served by a LAN.
WANs use the services of carriers, such as telephone companies, cable companies, satellite systems, and network providers.
WANs use serial connections of various types to provide access to bandwidth over large geographic areas.