Superposition and interference of waves
Two matters cannot be in the same location. But, two or more waves can be in the same space and at the same time. Throwing two stones into the pond creates an interference pattern due to each wave.
Constructive interference and destructive interference
When waves from two sources overlap each other with the same phase, the wave’s amplitude increases. (constructive interference)
If the waves from two sources overlap each other with opposite phases, the waves’ amplitude decrease. (destructive interference)