Wave interference is a property of a wave that occurs when two waves travelling at the same time in the same medium meet or superpose at a point.
Interference of a wave may be constructive or destructive. Constructive interference occurs when waves meet and get in phase with each other such that the resulting amplitude is larger than the amplitude of individual wave. Therefore, if two wave with the same amplitude undergo constructive interference then the amplitude of the resulting wave will be twice the amplitude of individual waves.
Destructive interference occurs when two waves travelling in the same medium at the same time meet such that they completely cancel each other out. For two waves to interfere destructively, they must be of the same amplitude and traveling in the opposite direction, so as to produce zero amplitude.
