Secondary education is the stage of education following primary education. Secondary education includes the final stage of compulsory education and in many countries it is entirely compulsory. The next stage of education is usually college or university. Secondary education is characterized by transition from primary education for minors to 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, sixth-form, colleges, vocational schools and preparatory schools, and the exact meaning of any of these varies between the systems.