Wi-Fi’ is not a technical term. However, the Alliance has generally enforced its use to describe only a narrow range of connectivity technologies including wireless local area network (WLAN) based on the IEEE 802.11 standards, device to device connectivity [such as Wi-Fi Peer to Peer AKA Wi-Fi Direct], and a range of technologies that support PAN, LAN and even WAN connections.
If you have found something like this:
Wi-Fi means wireless fidelity. In short, an internet connection without the use of wires or cables.
Is wrong! because…
Phil Belanger, a founding member of the Wi-Fi Alliance who presided over the selection of the name "WiFi" writes:
Wi-Fi doesn’t stand for anything.
It is not an acronym. There is no meaning.
Wi-Fi and the ying yang style logo were invented by Interbrand. We (the founding members of the Wireless Ethernet Compatibility Alliance, now called the Wi-Fi Alliance) hired Interbrand to come up with the name and logo that we could use for our interoperability seal and marketing efforts. We needed something that was a little catchier than "IEEE 802.11b Direct Sequence". Interbrand created "Prozac", "Compaq" "oneworld", "Imation" and many other brand names that you have heard of. They even created the company name "Vivato".
The only reason that you hear anything about "Wireless Fidelity" is some of my colleagues in the group were afraid. They didn’t understand branding or marketing. They could not imagine using the name "Wi-Fi" without having some sort of literal explanation. So we compromised and agreed to include the tag line "The Standard for Wireless Fidelity" along with the name. This was a mistake and only served to confuse people and dilute the brand. For the first year or so( circa 2000) , this would appear in all of our communications. I still have a hat and a couple of golf shirts with the tag line. Later, when Wi-Fi was becoming more successful and we got some marketing and business people from larger companies on the board, the alliance dropped the tag-line.
http://www.boingboing.net/2005/11/08/wifi-isnt-short-for-.html