Beamforming is the manipulation of the signals fed to and received from complex antennas to create beams in space that focus power in a particular direction.
At the high bands, beamforming will mostly be used to increase range by energy focus, while at the mid and low bands below 6GHz, where attenuation is less of a problem, beamforming will be a key part of MIMO, the multiple-in multiple-out spatial channel technique that increases bandwidth for multiple devices in the same area. Although not part of the first release, 5G NR will support distributed-MIMO, where a user can receive different parts of the same data stream from multiple sites