Local Area Network (LAN)

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A local area network (LAN) is a group of computers connected by cabling and one or more network switches that are all installed at a single geographical location.

• might span a single floor in a building, a whole building, or multiple nearby buildings (a campus)
• all nodes and segments are directly connected with cables or short-range wireless
• Any network where the nodes are within about 1 or 2 km (or about 1 mile) of one another can be thought of as local
• LAN cabling and devices are typically owned and managed by the organization that uses the network
• Most cabled LANs are based on the 802.3 Ethernet standards

Example

• home/residential network
  • internet router and few computers, mobile devices, gaming consoles, printers
• small office/home office network
  • business-oriented network
  • possible uses centralized server and client devices and printer
  • often using a single internet router/switch/access point
• small and medium-sized enterprise (SME) network
  • supporting dozens of users
  • use structured cabling and multiple switches and routers
• Enterprise LAN
  • hundreds or thousands of servers and clients
  • require multiple enterprise-class switch and router appliances
• datacenter
  • network that hosts only servers and storage
  • no end user client devices

Wireless LAN (WLAN)

A wireless local area network (WLAN) uses radios and antennas for data transmission and reception.

• Most WLANs are based on the IEEE 802.11 series of standards
  • better known by its brand name, Wi-Fi
• Wi-Fi and Ethernet technologies complement one another and are often used together as segments within the same local network
  • allows computers with wired and wireless networking adapters to communicate with one another