Beamforming has been an integral part of each generation of Wi-Fi. It is a technique that narrows and projects a wireless signal towards a specific device, rather than having the signal broadcast in all directions. The connection is faster, stronger, and more reliable without having to boost broadcast power.
Simply put, beamforming focuses the radio signal towards the client device, and, if the client moves, the beam will follow.
Furthermore, because the signal isn't being cast where it's not needed, beamforming reduces interference from devices trying to pick up other signals.