Seconary education is the stage of education following primary school. Secondary education is generally the final stage of compulsory education. The next stage of education is usually college or university. Secondary education is characterized by transition from the typically compulsory, comprehensive primary education for minors to the optional, selective tertiary, "post-secondary", or "higher" education (e.g., university, vocational school) for adults. Depending on the system, schools for this period or a part of it may be called secondary schools, high schools, gymnasia, lyceums, middle schools, colleges, vocational schools and preparatory schools, and the exact meaning of any of these varies between the systems.