This chapter discusses several major theories of child development including psychoanalytic, learning, and cognitive theories. Psychoanalytic theories proposed by Freud and Erikson focus on internal drives and resolving psychosocial crises. Learning theories such as classical and operant conditioning examine how behaviors are influenced through reinforcement. Cognitive theories proposed by Piaget and Vygotsky consider how children acquire and construct knowledge through social interactions and experiences. Biological and ecological theories also influence understanding of child development. The chapter emphasizes evaluating theories based on their usefulness rather than labeling them as right or wrong.