what is superpostion principle.give an example to prove it?

When two or more waves of light travel simultaneously in a medium, the resultant displacement of each point of the medium at any instant is equal to the vector sum of the displacement produced by the two waves separately.

When we listen to an orchestra, we receive a complex sound due to the superposition of sound waves of different charctersistics produced by different insturments. still we can recognize separately the sound of different instruments.