LAN

• Local area networks, generally called LANs, are privately-owned networks within a single building or campus of up to a few kilometers in size.
• They are widely used to connect personal computers and workstations in company offices and factories to share resources (e.g., printers) and exchange information.
• Traditional LANs run at speeds of 100 Mbps to 1000 Mbps. Newer LANs operate at up to 10 Gbps.

MAN

• A MAN usually interconnects a number of local area networks (LANs) using a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to wide area networks (or WAN) and the Internet.
• A MAN may be wholly owned and operated by a private company, or it may be a service provided by a public company, such as a local telephone company.

WAN

• A wide area network (WAN) provides long-distance transmission of data, voice, image, and video information over large geographical areas that may comprise a country, a continent, or even the whole world
• WANs may utilize public, leased, or private communication devices, usually in combinations, and can therefore span an unlimited number of miles.