We have seen superposition used before with waves. If you remember, when two transverse waves meet, the superposition is to linearly add the two displacements.
The same effect applies to the potential, but with the potential we are interested in obtaining the electric field which is given by the gradient of the potential, so we want to concentrate more on the topology of the superposition.
For instance what happens as the waves just begin to meet? Can you describe the superposition in words?
For the two wave pulses shown above, as the two waves just begin to overlap as in scene 1, a saddle starts to develop between the two pulses. Because the pulses are of equal height, the superposition of the two at the midpoint between the pulses is twice as high as one of the pulses.
As the two pulses move closer together, the saddle becomes higher. This is the same topology we see when for the electric potential between two positive charges. Next explore the superposition of the electric potential for two positive charges.