A selective school is a school that admits students on the basis of some sort of selection criteria, usually academic. The term may have different connotations in different systems and is the opposite of a comprehensive school, which accepts all students, regardless of aptitude.
The split between selective and comprehensive education is usually at secondary level; primary education is rarely selective. At the university level, selection is almost universal, but a few institutions practice open admissions or open-door enrollment, allowing students to attend regardless of prior qualification.[clarification needed]