Answer: When the amount of sediments that are added to a coast and the amount of sediments removed from the coast are in equilibrium, then this equilibrium state is known as the sediment budget.
These sediments in the coastal areas are added by the ocean currents frequently striking at the base of a cliff, and also by the longshore current,and rivers that deposits the materials at the shore.
whereas, the materials are removed from the beach by the erosional processes, in which the longshore currents trnsports the sediments from the beach to the offshore.