Baby powder is a fine powder used on the skin to absorb moisture, reduce friction, and soothe skin, commonly for preventing diaper rash in infants. It is made from ingredients like talc, cornstarch, or arrowroot, and often contains added fragrance. The product is also used by adults for various purposes, such as absorbing sweat or as a dry shampoo, and it is available in both talc-based and cornstarch-based formulas.