The phrase "child's play" is a dual-layered term that refers both to the primary work of childhood and a common idiom for ease. Scientifically, it is the process through which children explore their environment and develop cognitive, social, and emotional skills. Linguistically, it dates back to the 13th century and signifies a task so effortless or simple that even a child could perform it. The Developmental Science of Play

Play is not merely a leisure activity; it is the "business" of childhood. It serves as a critical mechanism for brain development, impacting everything from manual dexterity to complex executive functions.