A comprehensive school is a state school that does not select its intake on the basis of academic achievement or aptitude. This is in contrast to the selective school system, where admission is restricted on the basis of selection criteria. The term is commonly used in relation to England and Wales, where comprehensive schools were introduced on an experimental basis in the 1940s and became more widespread from 1965. About 90% of British secondary school pupils now attend comprehensive schools. They correspond broadly to the public high school in the United States and Canada and to the German Gesamtschule.