A girl is a young female human being. The term is usually used to refer to a child or adolescent female, but it can also be used to refer to an adult woman. Girls are typically smaller and less physically developed than boys of the same age, and they have different sexual organs. Girls typically begin puberty between the ages of 10 and 14, and they reach physical maturity between the ages of 18 and 21. Girls are typically socialized to be more gentle, nurturing, and cooperative than boys, and they are often expected to take on more domestic responsibilities. However, there is a great deal of variation among girls, and not all girls conform to these stereotypes.