Children's Railway In Minsk, Belarus

The United Nations Convention on the Rights of the Child defines a child as "a human being below the age of 18 years unless under the law applicable to the child, majority is attained earlier." Ratified by 192 of 194 member countries. Some English definitions of the word child include the fetus and the unborn. Biologically, a child is anyone between birth and puberty or in the developmental stage of childhood, between infancy and adulthood. Children generally have fewer rights than adults and are classed as not able to make serious decisions, and legally must always be under the care of a responsible adult.
As a non-adult
Recognition of childhood as a state different from adulthood began to emerge in the 16th and 17th centuries. Society began to relate to the child not as a miniature adult but as a person of a lower level of maturity needing adult protection, love and nurturing. This change can be traced in painting: In the Middle Ages, children were portrayed in art as miniature adults with no childish characteristics. In the 16th century, images of children began to acquire a distinct childish appearance. From the late 17th century onwards, children were shown playing. Toys and literature for children also began to develop at this time.