It can be divided into wireless personal network(WPAN)
wireless local area network(WLAN)
wireless metropolitan area network(WMAN) and
wireless wide area network (WWAN)according to the coverage.

So what is the relationship between WI-FI and WLAN?
Wi-Fi = WLAN with 802.11 Technology
If you ask the average user what 802.11 wireless network is, they will be confused. Because most people are used to calling this technology Wi-Fi. Wi-Fi is a market that people around the world use as a synonym for 802.11 wireless networks.
