In this topic, you will learn how water can have different forms in different places.

Oceans and seas are large bodies of salt water. They cover about 70/100 of Earth's surface. Oceans and seas are very deep and hold about 97/100 of all Earth's water. Water is also found in the atmosphere. Gases that surround Earth make up its atmosphere. In the atmosphere water is in a gas state and is called water vapor. The atmosphere always has some water vapor. The amount of water vapor in the atmosphere depends on the location.There is more water vapor in the atmosphere over or near large bodies of water than over deserts.

About 2/100 of Earth's water is found in glaciers and in the polar ice caps. A glacier is a heavy, solid mass of ice. Some glaciers form high in the mountains and flow slowly down steep valleys. An ice cap is a thick sheet of ice covering a large area of land. Greenland and Antarctica are covered with ice caps. Some glaciers flow across land until they reach the sea. These large chunks often break off and float out to sea as icebergs.

Oceans and lakes are water that you can see on Earth's surface. There is also water below the ground. Some water soaks into the soil to become soil water. Some soil water is used by plants. The rest soaks through the soil and into the underground rocks. Many rocks have tiny spaces and cracks between them. Water passes down through these cracks until it reaches a layer of solid rock that it cannot pass through. It then begins to fill the spaces and cracks in the rocks above. Water stored in these cracks and spaces in underground rock is called groundwater.

Living things also contain water. Water makes up at least half the weight of most plants and animals. When you bite into an apple or some other fruit, the juice is made of water.

Without water there would be no life on Earth. Water is one of our most valuable resources. You use water for drinking and bathing. All the food you eat needs water to grow.