Explain longshore drift

Longshore drift is a natural process occurring as waves wash onto beaches. insert diagramThe waves are washed onto the beach at an angle, so the 'swash' occurs diagonally. As the water recedes back into the sea it drags the sand etc in the 'backwash' in a straight line. This means that the collected material is moved along the beach, often accumulating at one end which may eventually form a spit.