It's simple and inexpensive.Credit: Getty ImagesKey PointsStaying hydrated is essential for overall health, supporting digestion, temperature regulation, and other vital bodily functions.Plain water is the best drink for daily hydration because it's calorie-free, sodium-free, and supports key body processes.In some cases, like illness or heavy sweating, electrolyte-rich drinks or foods may help replenish lost fluids.Staying hydrated is one of th…