Normal saline (0.9% sodium chloride) is an isotonic solution commonly used for fluid replacement. Ringer's lactate, also known as lactated Ringer's solution, contains electrolytes and lactate, making it useful for treating dehydration and restoring electrolyte balance. D5W (5% dextrose in water) provides both hydration and a source of carbohydrates. Each of these solutions serves specific clinical purposes, and the choice depends on the patient's condition and needs.