Delhi, officially the National Capital Territory of Delhi is a center-state and metropolis of India. This includes New Delhi which is the capital of India. Being the capital of Delhi, the three units of the central government - the headquarters of the executive, parliament and judiciary, are established in New Delhi and Delhi. Delhi is an important center of education in India. Along with the development of Delhi, education has also grown rapidly. Primary education is usually public. In a very large proportion, children are studying in secondary schools. Students in the educational institutions here come from all parts of India. There are many government and private education institutes. Private schools in Delhi—which use either English or Hindi as the language of instruction—are affiliated to one of three administering bodies, the Council for the Indian School Certificate Examinations (CISCE), the Central Board for Secondary Education (CBSE) or the National Institute of Open Schooling (NIOS). Schools and higher educational institutions in Delhi are administered either by the Directorate of Education, the NCT government or private organisations.