What is metropolitan area network?

A metropolitan area network is a large computer network spanning an area of a few city blocks to the area of an entire city. Sometimes, it is also referred as Municipal Area Network.  The networking technologies used in municipal networks include Asynchronous Transfer Mode (ATM), FDDI, and SMDS. However, these technologies are increasingly being displaced by Ethernet-based connections. Its links between local area networks have been built with wireless links using either microwave, radio, or infra-red laser transmission. Most companies rent or lease circuits from common carriers because laying long stretches of cable is expensive

(source: Wikipedia)