The size of a wave depends on its fetch. The fetch is the distance a wave travels. The greater the fetch, the larger the wave. Wind also has a significant effect on the size of waves. The stronger the wind the larger the wave.
As a wave approaches a beach it slows. This is the result of friction between the water and the beach. This causes a wave to break.
There are two main types of wave. These are constructive and destructive waves. :
Constructive waves build beaches. Each wave is low. As the wave breaks it carries material up the beach in its swash. The beach material will then be deposited as the backwash soaks into the sand or slowly drains away. These waves are most common in summer.