by Janet Grischy

Created on: April 03, 2009

WAN, LAN, and MAN are all terms for networks of interconnected computers. Chances are very good that every casual computer user has been on at least two of these networks, and quite likely all three.

LAN stands for local area network. A LAN is composed of computers and peripherals that are all in the same location. It is usually wholly owned by its users. Small to medium-sized businesses with no computers at distant branches are usually connected in a local area network. People who have more than one computer at home often have them connected in a LAN. Some LANs, however, connect thousands of computers.

Advantages of a LAN are that they can have good bandwidth and that all the computers connected to the network can share peripherals like faxes, scanners, and printers. In a single building, home, or school, sharing peripherals can save money and stretch resources. These systems can also share files, if the network is set up that way, and applications like Word and GIMP. A LAN is often connected to the internet through a router and an ISP, an internetservice provider.

The internet is a WAN. A WAN is a wide area network. It is a network that generally connects a collection of LANs, though single computers connect as well. WANs are commonly used by big businesses, whether statewide or multinational, but also by governmental, educational, research or philanthropic enterprises.

WAN networks may be maintained by the businesses that use them, but they are often provided and maintained by outside contractors. They may run over leased lines. Some WAN systems, such as the internet, are collectively owned and maintained.

Advantages of using a WAN include increased efficiency, ease of communication, and lowered costs. Disadvantages include security problems, training costs, and maintenance problems. Large enterprises will dedicate personnel to maintaining their WAN.

MAN is the acronym for metropolitan area network. It connects computers in a network that is usually larger than a LAN but smaller than a WAN. Often MAN connects the computers of a city (hence the name) but it may connect the machines of a University or similar institution. Some cities with MAN include London, England; Geneva, Switzerland; and Lodz, Poland. Not all computers in a MAN area need be connected to the network, but the MAN will often connect as a whole to the internet, and thus provide a connection for those who choose to use it.

Advantages of a MAN are efficiency and shared access. All the computer-owning residents of the area have equal ability to go on line. Some disadvantages have to do with cost, and with politics. Some people do not feel that it is the job of government to provide internet access for all, nor the responsibility of taxpayers to fund it. As always, security is also a concern.

WAN, LAN and MAN may be wireless or hardwired, though the trend seems to be wireless. They are all useful networks of computers, whether the small home LAN, the city or campus MAN, or the globe-spanning WAN called the internet.

Learn more about this author, Janet Grischy.
Click here to send this author comments or questions.