The two standard types of wireless keys support WEP and WPA encryption. To use a wireless key on a home network, administrators first set up an encryption method on the router (either WEP or WPA) and choose a value for the appropriate key. Then, the administrator sets the same value on each wireless device connecting to the router. Wireless keys are hexadecimal numbers that vary in length (but are typically between 128 and 256 bits long) depending on the encryption method used.
Although technically not a wireless key, network passphrases can sometimes be used in place of a WEP or WPA key.