In the computing world, the term "wireless" can be rather ambiguous, since it may refer to several different wireless technologies. The two most common types of wireless capabilities computers have are Wi-Fi and Bluetooth.
Wi-Fi is the technology used for wireless networking. If your computer has a wireless card, it is most likely Wi-Fi compatible. The wireless card transmits to a wireless router, which is also based on the Wi-Fi standard. Wireless routers are often connected to a network, cable modem, or DSL modem, which provides Internet access to anyone connected to the wireless network.
Bluetooth is the technology often used for wireless keyboards and mice, wireless printing, and wireless cell phone headsets. In order to use a device such as a Bluetooth keyboard or mouse, your computer must be Bluetooth-enabled or have a Bluetooth adapter installed.
Computers may also use other wireless technologies aside from Wi-Fi and Bluetooth. Products such as remote controls and wireless mice may use infrared or other proprietary wireless technologies. Because of the many wireless options available, it is a good idea to check the system requirements of any wireless device you are considering buying.