Wi-Fi devices:

A device that can use Wi-Fi  can connect to a network resource such as the Internet via a wireless network access point. 

  An optional feature added in 2007, called Wi-Fi Protected Setup (WPS), had a serious flaw that allowed an attacker to recover the router's password.The Wi-Fi Alliance has since updated its test plan and certification program to ensure all newly certified devices resist attacks. The use of WPS greatly reduces the time required to gain access by the use of so called "brute force" attacks.