I really like the brand vita coco, here is their information page.
After reading several articles, coconut water comes from fresh green coconuts and it is the water inside of the coconut. The coconut milk is grated coconut into water and then processed into milk.
Some of the articles said the sodium was not high enough to be a good sports drink after strenuous exercise, another article said it was too high in sodium. All the articles say it is an excellent source of potassium.
More information on coconut water: here and here
So tell me do you like coconut water?