Hey there,
There are many ways waves can shape Earth's surface. For example, the waves can constantly brush up against a rocky ledge or cliff, and it can shape the cliff. It can change it's shape and/or form and can break away the rock or land. The waves can also bang against the rock, making it loose and the rock shapes itself by falling off or apart. This is otherwise known as erosion.
Best Of Luck,
- I.A. -