A child is a young human. Depending on context it may mean someone who is not yet an adult, or someone who has not yet hit puberty (someone who is prepubescent).
In law, a person who is not yet a legal adult is known as a minor (known in some places as an juvenile, or, in others, as a infant). For example, in many countries a person under the age of 18 is a minor. Most countries give additional legal protection to minors despite their underage status, and all UN member states except the United States and Somalia have ratified the United Nations' Convention on the Rights of the Child, although not all of them have followed it.
Pediatrics is the branch of medicine relating to the care of children. It encompasses ages from prenatal to teenagers and even young adults (ages 0-21 years).
Terms for stages of age-related physical development include:
Preadolescence (preteen, or late childhood. The child in this and the previous phase are called schoolchild (schoolboy or schoolgirl), when still of primary school age.)
Earlier branches of economics see humans in terms of labour for production, means of persuasion or protection, which tend to be skills acquired only in adolescence and adulthood. The human development view is more evident in sports, music and other performing arts, such as acting where the child begins training often as early as three years of age. Think of Tiger Woods and his early practice golfing.
