What is the term used for the area where groundwater is located?

The term for the area where groundwater is located is "aquifer." An aquifer is specifically defined as a geological formation that can store and transmit significant amounts of groundwater. It is typically composed of materials like sand, gravel, or porous rock that allow water to flow through them.

The water table is the upper surface of the saturated zone where the ground transitions from being completely dry to being filled with water, but it does not directly refer to the area itself where the groundwater is stored. A reservoir is a large natural or artificial lake or storage area for water, which is not synonymous with groundwater storage. The term "groundwater zone" is less commonly used in scientific literature and is not the standard term for the actual storage area of groundwater. Understanding these distinctions helps clarify the role of aquifers in the hydrological cycle and their importance as sources of freshwater.