At the points where the two pulses overlap, the resultant displacement is the vector sum of the displacements due to each of the two wave pulses. This is called the principle of superposition.
Two or more waves can traverse the same space independent of each other. Each one travels as if the other were not present. This property of the waves enable to tune to a particular radio station even though the waves broadcast by a number of radio stations exist in space at the same time. This principle is used to explain the phenomena of interference of waves, formation of beats and stationary or standing waves.