Ocean

The largest body of water on Earth, oceans are massive collections of saltwater that span approximately 71% of the planet’s total surface areas.
Sea

A sea is generally defined as a part of the ocean that is at least partially bordered by land. While there is no very clear-cut definition between a sea and an ocean, seas are much smaller.
River

Rivers are bodies of water that flow downhill from a source to an outlet by the force of gravity. Even though there is no technical distinction between a river, stream, and creek, most people think of rivers as the largest of the three.
Lake

A lake is defined as any body of surface water. This means that lakes sit—you guessed it—at the surface of the Earth where they collect runoff from local streams and rivers.
Spring

Springs are a funky type of water body that forms when water from an aquifer or another type of groundwater bubbles its way up to the surface of the earth. This often happens in valleys, but you can find them pretty much anywhere.