Since the inception of modern day wireless networks, we have used the IEEE given name. Now, thanks to the WiFi-Alliance we have a new naming scheme.
802.11-Wi-Fi 0 2.4GHz Only
802.11a-Wi-Fi 1 5GHz Only
802.11b-Wi-Fi 2 2.4GHz Only
802.11g-Wi-Fi 3 2.4GHz Only
802.11n-Wi-Fi 4 2.4GHz or 5GHz
802.11ac-Wi-Fi 5 5GHz Only
802.11ax-Wi-Fi 6 2.4GHz or 5GHz
Yes the next standard in WiFi will simply be called WiFi 6.
IEEE: Organization that creates the standards
WiFi-Alliance: Organization tasked with marketing the WiFi branding and certifying compliance to the standards.