From Mycomputer Notes

A wide-area network (WAN) is a data communications network that connects user networks over a large geographical area. WANs have several important characteristics that distinguish them from LANs. In this module is about providing an overview of WAN technologies and protocols.

This module is about understanding the physical layer components of a router. This knowledge builds a foundation for other information and skills that are needed to configure routers and manage routed networks.

WAN

WAN

Data communications network that spans a large geographic area such as a state, province, or country. WANs often use transmission facilities provided by common carriers such as telephone companies.

These are the major characteristics of WANs:

• They connect devices that are separated by wide geographical areas.
• They use the services of carriers such as the Regional Bell Operating Companies (RBOCs), Sprint, MCI, and VPM

Internet Services, Inc. to establish the link or connection between sites. 

• They use serial connections of various types to access bandwidth over large geographic areas.