Coconut water is the clear liquid found inside a young, green coconut which is usually about the size of a basketball. Ideally, young coconuts are harvested at 5-7 months of age, to contain the most water.
As the coconut matures, the liquid is replaced with coconut "meat". The greatest nutrient health benefits of coconut water comes from drinking the water of the young coconut, not the mature coconut milk, which is generally lower in nutrients.
Coconut water has been consumed for centuries in tropical countries and is believed to treat a variety of health-related ailments. In Sanskrit, coconuts are called "kalpa vriksha" which means "tree which gives all that is necessary for living".
In certain emergency situations, coconut water has been used for IV hydration due to its high electrolyte content and the fact that it is sterile if used directly