Water is a tasteless, odorless, and nearly colorless (it has a slight hint of blue) substance in its pure form that is essential to all known forms of life and is known also as the most universal solvent.
Water is an abundant substance on Earth. It exists in many places and forms: mostly in the oceans and polar ice caps, but also as clouds, rain water, rivers, freshwater aquifers, and sea ice. On the planet, water is continuously moving through the cycle involving evaporation, precipitation, and runoff to the sea.
Water that humans consume is called potable water. This natural resource is becoming more scarce in certain places as human population in those places increases, and its availability is a major social and economic concern.
(From Wikipedia, the free encyclopedia.)