This document outlines the major stages of human development from pre-natal period through late adulthood. It describes key aspects of physical, cognitive, social, and emotional development that occur during each phase. The document also discusses developmental tasks, which are goals that should be achieved during each life stage in order to support healthy development and functioning in later stages. Some examples of developmental tasks include learning to walk during infancy, developing a sense of identity during adolescence, and adjusting to retirement during late adulthood. Accomplishing the tasks of earlier stages helps to achieve tasks in subsequent stages.