When it rains, the Earth absorbs a part of the rain-water while the remaining water evaporates. The absorbed water seeps into the ground and keeps on going down through the holes and cracks in the Earth.
On its way down, the water passes through rocks and sometimes collects there. When this collected water finds an opening to come out, it bursts out as a spring.
Sometimes the water accumulated inside the Earth has to pass through areas containing sulphur or lime. This sulphur and lime dissolves in water. When this water comes out in the form of a spring, they are called sulphur springs. On mixing with sulphur, there is a chemical reaction which heats the water, and water even smells of sulphur. In India, there are many such springs in Kashmir, Haryana and Uttar Pradesh.
Sometimes water from the Earth's surface reaches deep down in the Earth's interior. It then starts boiling due to the Earth's heat. When this hot water comes out through an opening in the Earth in the form of a spring, they are called hot springs. There are many such springs in the United States of America and New Zealand.
