An illiterate person is unable to read or write simple sentences. Literacy rates in India are 62.8% for adults and 81.1% for youth, with large gaps between male and female rates. Causes of illiteracy include economic conditions, lack of awareness, caste divisions, gender inequality, and lack of schools in rural areas. While India's overall adult literacy rate improved to 74.04% by 2011, rates vary significantly between states and sexes, highlighting the need for continued efforts to expand educational access and quality.