Post-secondary or tertiary education, also referred to as third-stage, third level education, or higher education, is the non-compulsory educational level following the completion of a school providing a secondary education, such as a high school, secondary school, or gymnasium. Tertiary education is normally taken to include undergraduate and postgraduate education, as well as vocational education and training. Colleges and universities are the main institutions that provide tertiary education (sometimes known collectively as tertiary institutions). Examples of institutions that provide post-secondary education are vocational schools, community colleges and universities in the United States, the TAFEs in Australia, CEGEPs in Quebec,and the IEKs in Greece. They are sometimes known collectively as tertiary institutions. Tertiary education generally results in the receipt of certificates, diplomas, or academic degrees.

Higher education includes teaching, research and social services activities of universities, and within the realm of teaching, it includes both the undergraduate level (sometimes referred to as tertiary education) and the graduate (or postgraduate) level (sometimes referred to as graduate school). In the United Kingdom post-secondary education below the level of higher education is referred to as further education. Higher education in that country generally involves work towards a degree-level or foundation degree qualification