Water comes from three main natural sources: rain water, underground water and surface water. Rain water includes rain, snow and other forms of precipitation. Underground includes water tables and water hidden in the soil. Surface water includes oceans, rivers, lakes, ponds and any other above-ground collection of water.
These natural sources of water supply most of the water for the planet. Precipitation replenishes underground and surface water supplies and is a key part of the water cycle. Underground water sources are not immediately accessible but are one of the most important sources of water for human consumption. Underground water supplies are accessed through wells, or from springs when the pressure gets too great.
Surface water is the easiest to access and the most abundant, though most surface water is salt water, and, therefore, not suitable for drinking by most species. Surface water is used for drinking and for producing hydro-electric power as a renewable, clean energy source. This water comes from precipitation, springs and the melting of glaciers. Rivers eventually empty into the ocean.
A large portion of fresh water is trapped in glaciers, the ice caps and the atmosphere. The frozen water is not accessible directly by humans, but it does help to replenish surface water supplies as the global temperature rises and the ice melts.