What is the difference between WAN and LAN?

Local Area Network (LAN): Local Area Network (LAN) is a computer network, which is limited to a small office, single building, multiple buildings inside a campus etc. Typically a Local Area Network (LAN) is a private network owned and maintained by a single organization.

Wide Area Network (WAN): A Wide Area Network (WAN) spans over multiple geographic locations, which is composed of multiple LANs. It is nearly impossible for a small to medium organization (except Network Service Providers) to pull network cables between their two offices in two different countries located 1000s of kilometers away. Network Service Providers (also called as ISPs) provide the connectivity solutions for Wide Area Networks (WAN).

It is a good question related to Management of Telecommunications, precisely "Networks Location".

*(WAN) is a Wide Area Network:  computers are connected together but they are far away and may not be in a same country even! 

*(LAN) is Local Area Network:  all the computers are connected in one location.

*It is worth-mentioning that there is a network so-called (PAN) Personal Area Network, for instance, the network type between your mobile phone and your personal computer "short distance".