A Wide Area Network (WAN) is a data network that spans a large geographic area and often uses communication services provided by carriers.

Large companies and government entities use wide area networks to share data among employees, clients, buyers and suppliers from a range of geographical locations. This mode of telecom networking allows a business to successfully complete its daily tasks despite having a distributed workforce.

WANs are used to connect local area networks (LANs) and other kinds of networks, facilitating seamless communications among colleagues in different parts of the world. Many WANs are custom-built for a certain organization and are private. Others provide connections from an organization’s LAN to the internet. WANs are often built using leased lines. At each end of the rented line, a router links the LAN on one side with a second router inside the LAN on the other.