What is NIOS board?? Give me some details.

National Institute of Open Schooling popularly known as NIOS is an open school established to provide distance education. The main objective of this board is to spread education to all segments of society, including the remotest parts of the country. It was established to increase literacy in India. Students who failed in qualifying examination of class 10 or class 12 from any other board can also complete their class 10 or class 12 in the same year with On-Demand examination facility of NIOS. It is equivalent to other boardin India.