How Does Difference between waves and swell Work?

Waves and swell are both moving ridges of water, but they differ mostly by where they come from and how far apart their peaks sit.

Imagine you are in a bathtub with the tap running. The water jiggles right around the spout because the current is pushing it. Waves are like that bathtub water. They are created by wind blowing directly over the spot where you are standing. If you look at the sky and see clouds rushing by while the ocean ripples, those are local waves. They often look choppy and messy because they are still being pushed by the nearby wind. The distance from one peak to the next is usually short, so you might feel a quick thump-thump as each wave hits your legs.

Now think of a long line of toy boats floating down a hallway after someone pushes the first one hard at the start. Swell waves are like those boats. They were created by strong winds far away, perhaps on the other side of the ocean. After the wind stops or moves away, the energy keeps traveling across the water surface for days. These waves have smooth, rounded tops and are spaced much farther apart.

When you go to the beach and see clean, rolling hills of water that don't change much even if the local breeze is light, those are swells. They feel powerful but steady, like a gentle giant breathing in and out. You do not need strong wind right above your head to get swell; it can travel thousands of miles without losing its energy.