The materials that are eroded from the coast are usually transported along the coast by waves and currents before they are deposited elsewhere.
The Longshore Drift
When waves approach a coast at an angle, the swash brings the sediment up onto the coast at the same angle.
Due to friction and the pull of gravity, the sediment is then brought seawards by the backwash at a right angle to the coast.
The sediment is picked up again by the next wave and carried up and then down the coast again.
This repeated zig zag movement of the sediment shifts the sediment along the beach.
A long shore drift is the movement of sediment along the coast when waves approach the coast at an angle