A telecommunications network that extends over a large geographic area for the primary purpose of connecting smaller computer networks (LANs) and metro-area networks (MANs).

The internet may be considered a public WAN. Private wide area networks can be created through leased WAN facilities.

Smaller private networks may be bridged across the public Internet by using a virtual private network (VPN), or an IP tunnel, which encapsulates packets, including their headers containing the private addresses, in a protocol layer during transmission across the public network. The encapsulated packets may then be encrypted for the transmission across public networks to secure the data.