Most of the water we see each day is in ponds, rivers, oceans, streams, lakes, puddles, and other places on top of the ground. What we don’t often see is the water that soaks into the ground. We use a special word to describe water that has gone underground: groundwater.
you were to travel underground, you would eventually get deep enough to
find all the rock around you soaked with water—You’d have
entered the saturated zone! The water in the saturated
zone is called an aquifer. The height of water in the saturated zone is
called the water table. In dry places, the water table
is very deep, but in moist places, the water table is very shallow. When
the water table is higher than the surface of the ground, there are streams,
rivers, and lakes on the land.