The difference between a LAN and WAN is size. A LAN (local area network) is confined to a small area, typically a household or small business. A WAN (wide area network) is the collection of multiple LANs. So the Internet is an example of a WAN. It is a massive collection of different LANs. For instance, my LAN and your LAN help make up the WAN which is the internet, a connection of many LANs. There are also things called PANs and MANs, which aren't as prominent today, but still interesting.