The water that is trapped underground is called groundwater. Some of the groundwater seeps into rivers and lakes and may even end up back in the sea. In some places, groundwater is pumped to the surface to be used in irrigation, or treated and used for drinking water. Water is pumped to towns to be used in houses and factories. In factories it is used to wash and cool machines.
More water is used in factories than in homes.
People use water in homes for drinking, cooking and cleaning. Sometimes water has to brought to land that otherwise might be too dry for crops and animals to survive. This is called irrigation and is done by building pipelines and canals to bring the water from the rivers and lakes. Water is also used to produce electricity either by heating it, or by using its power as it falls from dams and waterfalls to turn big turbines. People also use water for recreation, such as swimming, fishing and boating.