Internet

A local area network is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport.

A wide area network is a computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks.

A metropolitan area network is a large computer networks t that usually spans a city or a large campus.

A gateway connects networks that use different link layer protocols.

A router connects network that use the same link layer protocols.

A unique address that identifies a computer or other electronic device on network