Breast development refers to the physical changes that occur in the chest area of females during puberty. This process is marked by the growth and enlargement of breast tissue, as well as the development of milk ducts and lobules. There are several synonyms for breast development, including mammary development, boob growth, bust enlargement, and chest maturation. These terms all refer to the same process of transformation that occurs as a girl's body prepares for potential pregnancy and lactation. While breast development can vary in duration and intensity between individuals, it is a natural and normal part of female development.