Water is essential for many critical functions in the human body. It helps regulate body temperature, creates saliva for digestion, lubricates and cushions joints and tissues, and aids in waste excretion through sweat, urine, and bowel movements. Water also carries nutrients and oxygen to cells, supports cognitive function, boosts energy metabolism, and helps maintain healthy skin and a strong immune system. Without sufficient water, bodily functions deteriorate, leading to dehydration and serious health consequences.