What is groundwater?

Groundwater refers specifically to water that is located beneath the earth's surface. This water fills the spaces and pores found in soil and also occupies fractures within rock formations. Groundwater is a crucial component of the hydrological cycle and serves as a significant source of drinking water for many populations.

This definition distinguishes groundwater from other types of water sources, such as surface water, which includes rivers, lakes, and reservoirs found on the earth's surface. Groundwater is not found in the atmosphere—that would refer to water vapor and precipitation. Additionally, while reservoirs do hold large quantities of water, they are typically man-made structures that contain surface water. Thus, understanding groundwater is essential for water management, hydrology, and environmental science since it plays a vital role in sustaining ecosystems and human activities.