Beamforming is a technique to strengthen the signal used in radio frequency data transmission. It is the most used factor in 5G cellular networks and Wi-Fi. In electromagnetic radio frequency wireless communication, the antenna or multiple antennas are sued to transmit the signal and mostly they use omnidirectional antennas.
Three (3) main categories of the antenna are (a) Omni-directional (b) Directional and (c) Semi-directional.
For devices or networks that are intended for users all around, omnidirectional antennas are used so that users from all sides can receive the signal and get connected to the network. The output signal from an antenna spread all sides equally. But sometimes, due to a concrete wall or obstacle, the signal strength decreases drastically and users can no longer receive the incoming signal anymore.
To eliminate this problem, a technique called "Beamforming" was invented. The theory is very simple but the procedure is highly complex. With the help of an advanced algorithm the device that has the beamforming can identify the receiver's approximate location and shape their output radio signal in such a way that it becomes easier for the receiver device to receive the signal.
So, finally, it can be said that in easy words Beamforming is nothing but focusing the signal towards any specific user to strengthen the signal.