The upcoming standard is called IEEE 802.11ax and it will be available starting in the fall of 2019.
The latest standard we’ve been using is called 802.11ac, and although we haven’t heard Wi-FI 5, the new standard will be widely promoted as Wi-Fi 6 (as the 6th generation).
The new Wi-Fi 6, 802.11ax uses both 2.4 GHz & 5 GHz and has features such as multi-user, multiple-input, multiple-output (MU-MIMO), Orthogonal Frequency Division Multiple Access (OFDMA) — allows more devices to simultaneously operate on the same channel — throughput of 9 to 10 gigabits per second in optimal conditions. It also supports WPA3.
Wi-Fi 5, 802.11ac (only uses 5 GHz)
Wi-Fi 4, 802.11n (uses both 2.4 GHz & 5 GHz)