A local area network (LAN) is a network used for connecting a business or organization's computers to one another. With a LAN, a concept that goes back to 1970, a company's employees can:
A local area network usually links computers (or resources such as printers) using a wired transmission medium (most frequently twisted pairs or coaxial cables) over a circumference of about a hundred metres. For larger spaces, the network is considered to be part of a network called a MAN (metropolitan area network), in which the transmission medium is better suited to sending signals over great distances.
A local area network is made of computers linked by a set of software and hardware elements. The hardware elements used for connecting computers to one another are:
The hardware devices alone are not enough to create a usable local area network. It is also necessary to set a standard access method between computers, so that they know how the computers are exchanging data, especially when more than two computers are sharing the same physical support. This access method is called a logical topology. The logical topology is carried out using an access protocol. The most common access protocols are: