Earth's water exists in three states and continuously cycles through the water cycle. Water covers over 70% of the planet as oceans and is essential for life. The water cycle involves evaporation, condensation, and precipitation, which impacts lives through fresh water availability. Most fresh water is frozen in glaciers and ice sheets, with the remainder flowing across and underground in drainage basins, streams, rivers, lakes, ponds, aquifers, and springs. Wells and artesian wells access underground fresh water sources.