Developmental stages refer to the various phases of growth and changes that an individual undergoes from birth to adulthood. These stages are characterized by specific physical, cognitive, and emotional changes that occur during different periods of life. The most commonly recognized stages of development are infancy, childhood, adolescence, and adulthood. Infancy is the stage from birth to about two years of age and is marked by rapid physical growth and development. During this period, infants develop their motor skills, learn to communicate, and form attachments with their caregivers. Childhood is the stage from two years old to adolescence. During this period, children continue to grow physically, but also experience significant cognitive and social development. They learn to think logically, develop their language skills, and form relationships with peers. Adolescence is the stage from thirteen to eighteen years of age and is characterized by significant physical and emotional changes. Adolescents experience puberty, which leads to the development of secondary sexual characteristics and the onset of sexual maturity. They also develop a sense of identity and begin to form more complex relationships. Adulthood is the stage that begins at the end of adolescence and continues throughout the rest of an individual's life. During this period, individuals continue to grow and develop, but at a slower pace. They may experience significant life changes such as marriage, parenthood, and career advancement. Understanding the various developmental stages is important for parents, educators, and healthcare providers. By recognizing the different stages of development, they can better support individuals in their growth and development, and provide appropriate interventions when necessary.