What is the difference between a LAN and a WAN?

What will be an ideal response?

A LAN is a group of computers connected by a network device, such as a hub or switch, that is located in a small area, such as an office building. LAN connections usually have high data transfer rates and use UTP cabling. A WAN is a network that covers a much larger area. It can be in the same state, or across several states, or across several countries. It usually connects several LANs together using high-speed, public communication links that are typically very expensive.