A local area network that transmits over the air typically in the 2.4GHz or 5GHz unlicensed frequency band. It does not require line of sight between sender and receiver. Wireless base stations (access points) are wired to an Ethernet network and transmit a radio frequency over an area of several hundred feet through walls and other non-metal barriers. Roaming users can be handed off from one access point to another like a cellular phone system.

The major wireless LAN standard today is the IEEE 802.11, more widely known by the "Wi-Fi" logo. 802.11 a, b, g and n are different standards which limit the maximum data transfer speed. Wireless Wi-Fi adapters (Wi-Fi transceivers) are either built into most new laptops or added via a PC card slot or USB. Wireless adapters for desktop machines can be plugged into a USB port or PCI slot.