Secondary education or post-primary education covers two phases on the International Standard Classification of Education scale. Level 2 or lower secondary education is considered the second and final phase of basic education, and level 3 upper secondary education or senior secondary education is the stage before tertiary education. Every country aims to provide basic education, but the systems and terminology remain unique to them. Secondary education typically takes place after six years of primary education and is followed by higher education, vocational education or employment. In most countries secondary education is compulsory, at least until the age of 16. Children typically enter the lower secondary phase around age 12. Compulsory education sometimes extends to age 20.
A high school senior classroom in the United States
Tertiary education, also referred to as third-level, third-stage or post-secondary education, is the educational level following the completion of secondary education. The World Bank, for example, defines tertiary education as including universities as well as trade schools and colleges. Higher education is taken to include undergraduate and postgraduate education, while vocational education beyond secondary education is known as further education in the United Kingdom, or included under the category of continuing education in the United States.
Students attend a linear algebra lecture at a tertiary institution: Helsinki University of Technology
Deakin University, one of Australia's 43 universities
The University of Pennsylvania, an American research university
University of Bologna, established in AD 1088, is the world's oldest university in continuous operation.
