This is because you constantly excrete water through sweat and urination, so your body needs to replenish the lost fluids. You won't live long without consuming a healthy amount of water. It's only possible to survive without water for a matter of days.
No, it's impossible. The body needs lots of water to carry out many essential functions, such as balancing the internal temperature and keeping cells alive. As a general rule of thumb, a person can survive without water for about 3 days.
