Wi-Fi (or Wi-fi, WiFi, Wifi, wifi), short for "Wireless Fidelity", is a set of product compatibility standards for wireless local area networks (WLAN).

Wi-Fi was intended to be used for mobile devices and LANs, but is now often used for Internet and wireless VoIP phone access. It enables a person with a wireless-enabled computer, a personal digital assistant (PDA), or a wireless VoIP phone to connect to the Internet when in proximity of an access point. The geographical region covered by one or several access points is called a hotspot.

Wi-Fi is a trademark of the Wi-Fi Alliance (formerly the Wireless Ethernet Compatibility Alliance), the trade organization that tests and certifies equipment compliance with the 802.11x standards.

Certified products can use the official Wi-Fi logo, which indicates that the product is interoperable with any other product also showing the logo.