What does the body use water for?

Water makes up over two-thirds of the healthy human body. It lubricates the joints and eyes, aids digestion, flushes out waste and toxins, and keeps the skin healthy.

Source: Dehydration @ NHS Choices

Image: Water Impact 0 by (Henningklevjer) - (Henningklevjer). Licensed under CC BY-SA 2.5 via Wikimedia Commons.