Child development involves the biological, psychological and emotional changes that occur in human beings between birth and the conclusion of adolescence. It is—particularly from birth to five years— a foundation for a prosperous and sustainable society.
Childhood is divided into three stages of life which include early childhood, middle childhood, and late childhood (preadolescence). Early childhood typically ranges from infancy to the age of 5 years old. During this period, development is significant, as many of life's milestones happen during this time period such as first words, learning to crawl, and learning to walk. Middle childhood/preadolescence or ages 5–10 universally mark a distinctive period between major developmental transition points. Adolescence often begins around the onset of puberty, marked as menarche or spermarche, occurring between 10 and 12 years of age, and ends upon acquiring the age of maturity.. Adolescence is characterized by maturation of the body, increase in capacity for learning, and emergence of personal identity. Developmental change may occur as a result of genetically controlled processes, known as maturation, or environmental factors and learning, but most commonly involves an interaction between the two. Development may also occur as a result of human nature and of human ability to learn from the environment.