What Is Wi-Fi or Wireless LAN Technology?

Wi-Fi, short for wireless fidelity, uses radio waves to connect computers to a local area network (LAN). Once networked, these computers can transfer information locally and connect to the Internet using a shared connection. Wireless local area networks (WLANs) operate in much the same way as traditional wired LANs; the main distinction is that in a LAN computers and routers are connected by cables while in a WLAN each computer and router requires wireless capabilities and uses those capabilities to exchange information.

In traditional networks, every computer connects to a router via an Ethernet cable. The router connects to a cable or DSL modem via another Ethernet cable, and then shares the Internet connection between all the linked computers. Networked computers can also transfer files to one another without relying on the Internet, provided that each computer's security settings allow it. Wireless networks work similarly, but replace the Ethernet cable between each computer and the router with a radio signal. Most Wi-Fi routers allow for a mix of wireless and wired connections on the same network.

Connecting a wireless network requires a wireless router and a Wi-Fi card in each computer. Wireless routers use an antenna to send and receive data from networked computers, each of which relies on a Wi-Fi card to communicate. Most laptops have Wi-Fi cards built-in, while desktop computers often require installation of a Wi-Fi add-in card. Some Internet providers offer devices called gateways in place of modems. Gateways include a built-in router, which takes the place of the stand-alone router in the network.

Wi-Fi's primary advantage is ease of use. With a WLAN, you can connect computers to the network without running cables across your house or having to drill through floors and ceilings. Having a Wi-Fi router also allows you to connect devices that lack Ethernet support, such as smartphones, tablets and some game consoles. Wi-Fi can also connect numerous devices simultaneously, whereas most home routers can only connect four computers via Ethernet before requiring additional hardware.

Even though Wi-Fi makes it easier to reach computers around your house, it also has range limitations. In a large building, or one with thick walls, the wireless router's signal may not reach every room. You can overcome this by moving the router or adding range extenders. Wi-Fi has potential security risks when left unsecured, but setting up a password using the latest security standard, WPA2, will leave your connection practically as safe as a wired network. Wi-Fi often provides lower speeds than wired connections do, and the connection speed tends to diminish when used far away from the router. These speeds still exceed those of most Internet connections, however, so they will only impact local network transfers (and not Web browsing) in most cases.