Wi-Fi® allows extending an ethernet IP network to operate over the air for the last 30m of access.
In other words, 802.11/Wi-Fi® is a collection of protocols that replace an ethernet cable.
"802.11" and "Wi-Fi®" are often used synonymously. Let's clarify these acronyms:
Refers to the suite of standards for implementing wireless local area networks (WLANs), created and maintained by the IEEE Standards Committee. The base current version is IEEE 802.11-2007.
A trademark owned by the Wi-Fi® Alliance (www.wi-fi.org), an industry trade association that promotes WLAN technology and certifies products if they conform to certain standards of interoperability. Similar in purpose/scope to the USB Implementers Forum (USB-IF).