Water table is the boundary below which the soil is saturated with water. Above the water table is the unsaturated zone, which has water and oxygen, whereas below water table, groundwater fills any space between soil and rocks.
The bottom of this saturated zone is impenetrable rock. Water table level within an area vary between seasons. In summer, water table drops due to less precipitation seeping into the ground due to lack of rain, and also due to trees using up the water in surface soil before it reaches the water table. In rainy season, water table rises. Water table can permanently drop due to overexploitation of groundwater. It is imperative that groundwater recharging is done for sustainable use of ground water.