Computers in a wide area network are often connected to each other using telephone lines.
When a computer uses an ordinary telephone line to connect to another computer, a modem is needed at each end of the link.
If an entire LAN needs to be connected to a WAN a special gateway needs to be set-up.
A Wide Area Network is not confined to one building. The computers and terminals forming part of the network can be spread around the world.
External communication links such as satellites, microwaves or telecommunication links will be used to connect the network. The connection must normally be paid for because the links are external.
LANs may be connected to WANs via a special gateway. Many Local Area Networks will be connected to the Internet in this way. The Internet is really a vast Wide Area Network.
Computer networks - LAN and WAN
This video shows a Local Area Network (LAN) in an office setting, and a Wide Area Network (WAN). Businesses and other organisations often link computers together to make communication more efficient. Each computer is linked to a central server which acts as a go-between within this LAN and beyond. A WAN links computers together over a wide geographical area. The internet is the ultimate WAN. Browsers are software packages which allow you to navigate around the internet.
Advantages / Disadvantages of WANs
Advantages and disadvantages of using Wide Area Networks are very similar to those for Local Area Networks, but on a larger scale. Security is even more important, particularly where WANs are connected to the public telephone system.