A. Wireless network adapters (also known as wireless NICs or wireless network cards) are required for each device on a wireless network. Some newer laptop computers incorporate wireless adapters as a built-in feature of the system. Separate add-on adapters must be purchased for most computers, however.
Popular wireless network adapters for PCs exist in the form of a PCMCIA "credit card." Macintosh computers use the distinctive AirPort card. USB wireless adapters that do not resemble cards also exist.
Strictly speaking, no wireless hardware other than adapters is required to build a small wireless LAN (WLAN). However, to increase the performance of a WLAN, accommodate more computers, and increase the network's range, wireless access points and/or wireless routers can be deployed.
Wireless routers function comparably to traditional routers for wired networks. One generally deploys wireless routers when building an all-wireless network from the ground up.
An alternative to routers, access points allow wireless networks to join an existing wired network. One typically deploys access points when growing a network that already has a wired switch or router installed. In home networking, a single access point (or router) possesses sufficient range to span most homes. Businesses in office buildings often must deploy multiple access points and/or routers.
Access points and routers often utilize a wireless antenna that significantly increase the communication range of the wireless radio signal. These antennas are optional and removable on most equipment. It's also possible to mount antennas on wireless clients to increase the range of wireless adapters. This is common practice for wardrivers, but add-on antennas are generally not required in typical home or business networks.