"Wi-Fi (pronounced /ˈwaɪfaɪ/) is a trademark of the Wi-Fi Alliance for certified products based on the IEEE 802.11 standards. This certification warrants interoperability between different wireless devices. In some countries (and in this article) the term Wi-Fi[1][2] is often used by the public as a synonym for IEEE 802.11-wireless LAN (WLAN). Not every IEEE 802.11 compliant device is certified by the Wi-Fi Alliance, which may be because of certification costs that must be paid for each certified device type. The lack of the Wi-Fi logo does not imply that a device is incompatible to certified Wi-Fi-devices. Wi-Fi is used by most personal computer operating systems, many video game consoles, laptops, smartphones, printers, and other peripherals.
WiFi is the "consumer" term - it was coined to rhyme with Hi-Fi, something that the average computer user is familiar with, so that the technology doesn't appear threatening or too "techy".
