Local area network

A local area network (LAN) is a computer network that interconnects computers within a limited area such as a home, school, computer laboratory, or office building, using network media. The defining characteristics of LANs, in contrast to wide area networks (WANs), include their smaller geographic area, and non-inclusion of leased telecommunication lines.
ARCNET, Token Ring and other technology standards have been used in the past, but Ethernet over twisted pair cabling, and Wi-Fi are the two most common technologies currently used to build LANs.

History

A conceptual diagram of a local area network using 10BASE5 Ethernet

The increasing demand and use of computers in universities and research labs in the late 1960s generated the need to provide high-speed interconnections between computer systems. A 1970 report from the Lawrence Radiation Laboratory detailing the growth of their "Octopus" network gave a good indication of the situation.
Cambridge Ring was developed at Cambridge University in 1974 but was never developed into a successful commercial product.
Ethernet was developed at Xerox PARC in 1973–1975, and filed as U.S. Patent 4,063,220. In 1976, after the system was deployed at PARC, Metcalfe and Boggs published a seminal paper, "Ethernet: Distributed Packet-Switching for Local Computer Networks."
ARCNET was developed by Datapoint Corporation in 1976 and announced in 1977. It had the first commercial installation in December 1977 at Chase Manhattan Bank in New York.

Wireless

As well as traditional cabling, many LANs are now based partly or wholly on wireless technologies. Almost all of today's smartphoness, tablets and laptops have wireless support built-in so a wireless local area network, or WLAN, gives users the ability to move around within a local coverage area and still be connected to the network. Wireless networks have become popular in domestic homes due to ease of installation, and in commercial complexes to offer easy network access to their staff. Visiting guest are often offered internet access via a hotspot service.