Local area network

A local area network (LAN) is a computer network that interconnects computers and other devices within a limited geographic area, such as a home, office, school, or building. LANs are distinguished from wide area networks (WANs) by their smaller scale, higher data transfer rates, and lower latency. They typically use wired technologies like Ethernet or wireless technologies like Wi-Fi. The physical and data link layers are defined by standards such as IEEE 802.3 for Ethernet and IEEE 802.11 for Wi-Fi.

LANs enable resource sharing among connected devices, including file storage, printers, and internet access. A common LAN configuration is the client-server model, where a server provides services to multiple clients. Alternatively, peer-to-peer networks allow each device to both provide and consume resources. Network devices such as switches and routers manage traffic within and between LANs.

Features

High bandwidth – Typical LAN speeds range from 100 Mbps to 10 Gbps or more, depending on the technology used.
Low latency – Because of short physical distances, data transmission delays are minimal.
Local control – The ownership and administration of a LAN are typically under the jurisdiction of a single organization or individual.
Multiple topologies – LANs can be arranged in star, bus, ring, or mesh topologies, with star being the most common using Ethernet switches.

History

Early computer networks in the 1960s and 1970s were often proprietary. The development of Ethernet at Xerox PARC in the 1970s, standardized as IEEE 802.3, provided a widely adopted open standard. The introduction of Token Ring by IBM offered an alternative. In the 1990s, Fast Ethernet and later Gigabit Ethernet dramatically increased speeds. Wireless LANs emerged with the IEEE 802.11 standard in 1997, enabling mobility without cables. The evolution of LANs continues with Power over Ethernet and software-defined networking.

Local area network