What is The boundary below which the ground is saturated with water.?

The boundary below which the ground is saturated with water is known as the water table. It represents the upper surface of the zone of saturation, where all the soil and rock pores are filled with water. The water table can fluctuate based on factors such as rainfall, evaporation, and groundwater extraction. Below this level, the soil and rock are typically unsaturated, containing both air and water.