What is a LAN?

From...

By Danielle Dunne

What is a LAN?

(IDG) -- A LAN, or local area network, is a group of computers, printers or other hardware that are all connected in a reasonably small geographic location like a office or home. A LAN makes it possible for the connected users to share files and applications that usually reside on a server or some type of shared computer.

LANs were invented to let people and computers share information. A server can have an application or database that is accessed by all the other computers on the LAN. This allows users to share information quickly and easily.

What is a server?

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In the world of information technology, a server isn't a person that waits on you in a restaurant, but an important piece of hardware. A server is a program on a computer (in offices the server is often kept in a closet type room) that literally serves up information or applications that are requested by clients -- other programs on connected computers. Most companies have Web servers that deliver Web pages to clients requesting them -- otherwise known as Web browsers like Internet Explorer and Netscape.

If a LAN is a local area network, then what is a network?

A LAN is a type of network and a network is a set of connected pieces of hardware. Networks can be put together in a variety of different ways, depending on the needs of the users. Each person or piece of equipment, like a printer, on a network is called a node. A network can have as few as three nodes -- or it could have thousands.

When were LANs invented?

Ethernet, a LAN technology, was invented in 1973 by Robert M. Metcalfe while he was working at Xerox PARC. Metcalfe invented Ethernet, an early form of a LAN, to let all the computers at PARC share printers and files. "We needed something that was fast, could connect hundreds of computers and span the whole building," Metcalfe told CIO magazine (a sister publication to Darwin) in late 1999.

There are other technologies, such as Token Ring, that have challenged Ethernet.

What about WANs?

A WAN or wide area network, is another kind of a network that consists of a group of connected computers or other hardware in a large area (as opposed to a LAN, which is a group of connected computers in a small area). A set of connected LANs makes up a WAN. The Internet is considered a WAN.

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