Human development from conception to death can be viewed from a number of perspectives, including biologic, cognitive, emotional, social, and moral. This chapter reviews the major features of various facets of development from infancy through toddlerhood, preschool, school-aged, preadolescence, adolescence, the transition into early adulthood, adulthood, and late adulthood. It includes consideration of developmental tasks and challenges, as well as the importance of the environmental influence of family, peers, school, and the broader social milieu. Psychological aspects and specific stages of elderly persons are also described.