Aquifer
An aquifer is an underground layer of water-bearing rock. Water-bearing rocks are permeable, meaning that they have openings that liquids and gases can pass through. An aquifer fills with water from rain or melted snow that drains into the ground.  Aquifers act as reservoirs for groundwater.

Ground Water
Ground water is the water that is found beneath the Earth’s surface (we know – why isn’t it called “underground water?!”). Ground water is important because it is where we get our water for drinking, agriculture business and household use. Everyday, people in the United States use 77.5 billions gallons of ground water.

Watershed
A watershed is the area of land where all of the water that is under it drains off and goes into the same body of water, whether it is a creek, river, marsh or ocean. Watersheds come in all sizes, a small watershed for a creek is part of a larger watershed for a river, which is also part of a larger watershed for a bay and so on.

Surface Water
Surface water is all the water above ground, which is found in rivers, ponds, lakes, and oceans.