Spring-head is a term used to refer to the source of a stream. It is also called a spring or a fountainhead. Other synonyms for spring-head are wellhead, spring source, aquifer, artesian well, and natural spring. A wellhead is the point where water is pumped from a well. An aquifer is an underground layer of water-bearing rock or sediment that stores and transmits water. An artesian well is a well that taps into an underground aquifer that is under pressure, causing water to rise to the surface without the need for a pump. A natural spring is a water source that flows naturally from the ground. Regardless of the word used to describe it, the spring-head is an important part of the water cycle and plays a vital role in sustaining life.