Why do we hear beats ?what is the difference between beats and interference?

Beats are also the interference but they are the intreference with respect to time and the optical interference that we are usually concern of is the interference with respect to space.as the constructive interference gives you the the fringes of maximum intensity and the destructive interference gives you thefringesof minimum intensity that we call the dark fringes in the same way constructive interference with respect to time gives you the sound of maximum intensity and these are called beats while at certain intervals we get the sound of minimum intensity that we can not hear.