Water is a transparent, colorless, tasteless, and odorless substance that is essential to all forms of life that we know of and is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms. Water covers 71% of the Earth's surface. It refers to the liquid state of that substance, but often refers also to its solid state or its gaseous state. Other than that water occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, and atmospheric humidity.Safe drinking water is essential to humans and other life forms even though it provides no calories or organic nutrients. Access to safe drinking water has improved over the last decades in almost every part of the world, but approximately one billion people still lack access to safe water. Ordinary rain water in many countries is polluted and therefore not safe to drink. This natural resource has become scarce with the growing world population, and its availability is a major social and economic concern. Once Margaret Atwood of Canada praised about water, We can not live without it, so maybe we should start respecting it.