What is the term for water that moves below the earth's surface and fills in empty spaces?

The term for water that moves below the earth's surface and fills in empty spaces is groundwater. Groundwater is found in the saturated zone of soil and rock, where it can occupy pores and fractures between the particles. This underground reservoir plays a crucial role in the hydrological cycle, as it supplies water to wells, springs, and can even contribute to surface water bodies through natural discharge.

Surface water refers to water in rivers, lakes, and streams that is visible on the earth's surface. Rainwater is simply precipitation that falls from the atmosphere and may contribute to both surface water and, through infiltration, groundwater. The term "storaged water" is not commonly used in hydrology and does not accurately define the water that resides underground. Groundwater is essential for ecosystems and human use, making it a key component of water management and environmental conservation.