Child development describes the physical, cognitive, emotional, and social growth of the child from birth to adolescence (some definitions include the prenatal period). The field of child development is part of a larger discipline known as developmental psychology (or human development in its interdisciplinary form), which is concerned with identifying and understanding systematic changes in the individual across the lifespan. Interest in child development stems from many disciplines—biology, psychology, sociology, education, medicine, and so forth. However, psychologists have played a predominant role in research and applied work in the area of child development.
Development is best described as a continual, cumulative, and holistic process. Changes in one aspect of development (e.g., language) have important implications for other aspects. While the average features of development proceed through a relatively regular, sequential process of change (normative development), there are individual variations (idiographic development).