The definition of literally rate is the ratio of population over 7 that can read, write and do arithmetic and apply it in their lives. These numbers are over inflated tbh because the standards to measure them are pretty debatable. Kerala may have 90% literacy rate, but the average literacy rate of India is supposed to be 80%+.

A person aged seven and above is considered literate in India if they can read and write with understanding in any language.

Literacy mostly means Reading skills. Goes a long way in a poor country with an abysmal record for primary education. Kerala also has a Higher % of school graduation compared to rest of India.