The document summarizes Jean Piaget's theory of cognitive development in children. Piaget believed that children's intellectual growth is based on their maturational level, experiences, and interactions with people and their environment. He identified four main stages of development - sensorimotor, preoperational, concrete operational, and formal operational - where children construct an understanding of the world through experiences that encourage either assimilation or accommodation of new information. Piaget's theory has significantly influenced education by helping caregivers and teachers understand child development and appropriate ways to support learning at different ages.