Beach material can be moved in four different ways. These are:
Sediment is carried by the waves along the coastline. The movement of the material is known as longshore drift. Waves approach the coast at an angle because of the direction of prevailing wind. The swash will carry the material towards the beach at an angle. The backwash then flows back to the sea, at 90° to the slope of the beach. The process repeats itself along the coast in this zigzag movement.