Wifi is a brand name for 802.11b, 802.11g, and 802.11a, it was conceived and marketed by the WiFi Alliance, formerly known as the WECA, the Wireless Ethernet Compatibility Association. In reality, it means very little, but has been used as a blanket term for 'Wireless Networking'. Purchasing gear that is WiFi branded gives you the assurance that the manufacturer paid for the brand license and passed the inter-operability testing required by WiFi Alliance. Sadly, this testing mostly covers Infrastructure Master and Client modes, but does not cover most implementations of 802.11 ad-hoc networking
Products may state that they are WiFi compatible and include proprietary extensions to the protocol, such as Super or Turbo modes. This means that the gear will operate at the 'standard' speeds and connect to other WiFi devices, but only when operated in a standard mode. You will realize none of the proprietary features if the gear you are using is different than what you are connecting to. Speed boosts and other Distance modifications do not fall under the standard compliance items, and will generally cause problems in a heterogenous environment.
