I would say breathing sweating and digestive also rehydration but your body does use water in it cellsban organs and tissues to help regulate temperature maintain other bodily functions but I can say that the Vital functions of water in the body or helps you can use flush out all that waste without you it’s your body‘s temperature cushions organs and tissues keeps your joints miss transport oxygen throughout your body helps keep your regular keeps your body tissues voice and helps keep your skin looking good
Hope this helps
