The school structure is divided into four key stages: the first three years in elementary school, Prathom 1–3, are for age groups 6 to 8; the second level, Prathom 4 through 6 are for age groups 9 to 11; the third level, Matthayom 1–3, is for age groups 12 to 14. The upper secondary level of schooling consists of Matthayom 4–6 for age groups 15 to 17 and is divided into academic and vocational streams. There are academic upper secondary schools, vocational upper secondary schools and comprehensive schools offering academic and vocational tracks. Students who choose the academic stream usually intend to enter a university. Vocational schools offer programs that prepare students for employment or further studies.