Water is a colourless, tasteless and harmless liquid that occurs naturally in the world.

Water occurs as liquid water, solid water, or ice, and water vapour, that we sometimes call 'moisture in the air'.

Water moves between liquid, solid and vapour (gas) all the time in nature. It forms part of the Water Cycle.

Water is important because so many things dissolve in it. As a result it can be used to carry substances far more easily than by any other means. Blood, for example, contains water; milk is mostly water; the sap of plants is mostly water, and so on.

Most scientists think that water is important for life wherever it might be found in the Universe. They think that we have so many forms of life in Earth because of plentiful water.

Water is also important because many things will float on it. This means that we can have ships carrying goods around the world.