Wi-Fi® allows extending an Ethernet IP network to operate over the air for the last 30 m of access.
In other words, 802.11/Wi-Fi is a collection of protocols that replace an Ethernet cable.
IEEE 802.11 and Wi-Fi are often used synonymously. Let's elaborate on these acronyms:
IEEE 802.11
It 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 802.11-2016.
Wi-Fi
It is 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. In purpose/scope, it is similar to the USB Implementers Forum (USB-IF).