Here's how it works:

* Precipitation: Rain, snow, sleet, or hail falls to the ground.

* Infiltration: Some of the precipitation soaks into the soil.

* Percolation: The water continues to move downward through the soil, filling spaces between soil particles.

* Groundwater: When the water reaches a layer of rock or clay that it cannot pass through, it accumulates and forms an underground reservoir called an aquifer. This water is known as groundwater.

Groundwater is a vital resource for drinking water, irrigation, and many other uses.