(iv) the nature and scope of the obligation to prioritise the introduction of compulsory and free primary education for all and to achieve progressively the full realisation of secondary, higher and fundamental education. Primary education • States have an obligation to guarantee access to and completion of compulsory and free primary education of good quality which meets the four A’s. • States must ensure that their laws, policies and practices do not inhibit or prevent children from accessing primary education. • States are obliged to eliminate school fees and minimise indirect costs imposed on students and parents or legal guardians. Secondary education and technical or vocational education • States have an obligation to make secondary education of good quality generally available and accessible to all by every appropriate means and, in particular, by the progressive introduction of free education. This includes technical or vocational secondary education. Higher or tertiary education • States have an obligation to make tertiary education equally accessible to all, on the basis of capacity and by every appropriate means and, in particular, by the progressive introduction of free education • Tertiary education should have flexible curricula and a variety of delivery systems to meet the needs of students in different social and cultural settings. • States have an obligation to ensure access to tertiary education for under-represented groups. Basic or fundamental education • States have an obligation to ensure the availability of basic education for individuals who have not received or completed primary education. • Functional literacy is especially important for those groups which are often excluded, such as girls and women, members of minority language groups and those with disabilities. • Basic education is an integral component of adult education and life-long learning and extends to children, youths and adults. 30