Question

what are beats?and what are the conditions of beats formation​

Answer 1

Beats. When two sound waves of different frequency approach your ear, the alternating constructive and destructive interference causes the sound to be alternatively soft and loud - a phenomenon which is called "beating" or producing beats.

Beats are generated when two sounds have similar frequency. The effect is that the sound's amplitude or volume oscillates or beats. The beat phenomenon is caused by constructive and destructive interference. The picture below shows the beat generated by two tuning forks with very close frequencies.