When we need to connect larger geographic areas like two states or few different countries together, we use what is called a Wide Area Network or WAN. This connection can be established over any distance via telephone lines or satellite uplinks.
The main difference between a MAN and a WAN is that the WAN uses cabling or radio waves over long distance. Otherwise the same equipment and protocols are used as a MAN. The main difference between a LAN and WAN is that while LAN typically covers a single office, WAN covers a much wider area.
Using a WAN, an office at New York can communicate with places like Singapore in a matter of minutes, economically. A WAN uses multiplexers to connect local and metropolitan networks to global communication networks like the Internet. To users, however, a WAN will not appear to be much different than a LAN or a MAN.
The Internet can be considered as the world's largest public WAN.
