Growth is physical change and increase in size. It can be measured quantitatively. Indicators of growth include height, weight, bone size, and dentition. The pattern of physiologic growth is similar for all people. However, growth rates vary during different stages of growth and development. The growth rate is rapid during the prenatal, neonatal, infancy and adolescent stages and slows during childhood. Physical growth is minimal during adulthood. Mostly these two terms are used interchangeably and taken as synonymous terms. Both relate to the measurement of changes occurred in the individual after conception in the womb of the mother. Change is the law of nature. An individual starting from a fertilized egg, turns into a full-fledged human adult. In this turn-over process he undergoes a cycle of changes brought about by the process of growth and development in various dimensions—physical, mental, social, emotional, etc. Therefore in the wider sense, both the terms growth and development can be used for any change brought about by maturation and learning and essentially is the product of both heredity and environment. In practical sense both terms are used to denote the changes in the organism’s physical as well as functional behavior. These changes which cover physical, emotional intellectual and social aspects of a human life are roughly divided into four major classes namely changes in size, changes in proportion, disappearance of old features and acquisition of new features. All these types of changes have qualitative as well as quantitative aspects and hence generally, growth and development go hand in hand. And the two terms are to be used collectively. Both, taken together, explain the total changes—functional as well as constitutional changes—in the body and behavior of the individual with the lapse of time after the conception. Terminology—these two terms have different meanings that can be put in the way given in this chapter.