Who is a literate person according to the Census 2001? Why is literacy considered important for the quality of the population?

According to the Census 2001 data, a person aged 7 years and above who can read and write with understanding in any language is treated as literate. Literacy is considered very important for the quality of a population because of the following:
(i) Only an well-informed and educated citizen can make intelligent choices and undertake research and development projects.
(ii) Low levels of literacy are a serious obstacle for economic improvement.