There are two different types of waves – constructive and destructive. They can affect the coastline in different ways. When a wave reaches the shore, the water that rushes up the beach is known as the swash. The water that flows back towards the sea is known as the backwash. The energy of the swash and backwash determine the type of wave.
Extract about waves from the BBC website. Click here to go to the BBC website to discover more.