A wide area network (WAN) is used to connect computers that are not close to one another. It is possible — and almost always the case — that LANs are connected to WANs. This enables small home or office networks to connect to wider networks, such as those across state or country lines. Most WANs connect through public networks, like the telephone system, or via leased lines. The Internet, which connects computers all around the world, can be considered the largest WAN in existence.