The terms growth and development are often used interchangeably. Actually, they are conceptually different. Neither growth nor development takes place all by itself.
Growth refers to quantitative changes in size, which include physical changes in height, weight, size, internal organs, etc. As an individual develops, old features like baby fat, hair and teeth, etc, disappear and new features like facial hair are acquired. When maturity comes, the second set of teeth, primary and secondary sex characteristics, etc, appear. Similar changes occur in all aspects of the personality. During infancy and childhood, the body steadily becomes larger, taller and heavier. To designate this change the term growth is used. Growth involves changes in body proportions as well as in overall stature and weight. The term growth thus indicates an increase in bodily dimensions. However, the rate of growth differs from one part of the body to the other. Development, by contrast, refers to qualitative changes taking place simultaneously with quantitative changes of growth. It maybe defined as
a progressive series of orderly, coherent changes. The term progressive signifies that changes are directional, that they lead forward rather than backward. Orderly and coherent suggest that a definite relationship between the changes taking place and those that precede or will follow them. Development represents changes in an organism from its origin to its death, but more particularly the progressive changes that take place from origin to maturity. Thus, development maybe explained as the series of overall changes in an individual due to the emergence of modified structures and functions that are the outcome of the interactions and exchanges between the organism and its environment.