Why does the ocean have waves?
For grown-ups: the science
Most ocean waves start when wind pushes across the water's surface.
Wind transfers energy to the ocean surface through friction and pressure differences, creating waves. In deep water, water particles mainly move in small circular paths while wave energy travels forward. As waves enter shallow water, the lower part is slowed by the seabed, causing the crest to steepen and break.
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Transcript
Look at the big blue ocean moving up and down. Why does it make waves?
Wind blows across the ocean's surface and pushes the water. The push makes little bumps that grow into waves.
Waves carry energy across the water, but most water mostly moves up and down. That is why a floating boat bobs.
Near the shore, the sea floor slows the bottom of a wave. The top tips forward and makes the wave break.
So waves usually begin when wind pushes water. Then they travel until the shore changes them.