A body of water is any place where water collects on Earth, from a tiny pond to a giant ocean. Water is always on the move or resting somewhere, and each kind of water body has its own special job.

A river is water that flows, always moving downhill from a high place toward a lower place. Rivers can be narrow or wide, and they carry water across the land like a natural road. Many rivers start in the mountains from melting snow or rain.

A lake is a large body of water that sits still, resting in a low spot in the land with ground all around it. Unlike a river, a lake does not rush anywhere fast, so the water mostly stays put. Lakes are great for swimming, fishing, and boating.

An ocean is the biggest body of water of all, stretching so wide that you cannot see the other side. Oceans are filled with salty water, while most rivers and lakes hold fresh water that is not salty. Together, the oceans cover most of our whole planet.

These waters are all connected in a big loop. A river often flows into a lake or all the way to the ocean, carrying its water along. When the sun heats the ocean, water rises into the sky, falls back down as rain, and fills the rivers again.

People need bodies of water to live. We drink fresh water, catch fish to eat, and use rivers and oceans to travel and carry goods on boats. That is why so many towns are built right next to water.