What do you mean by 'classical languages'?

What do you mean by ‘classical languages’?
Ans. In 2004, the Government of India declared that languages
that met certain requirements could be accorded the status of a ‘classical language’ in India. Languages thus far declared to be classical are Tamil (in 2004), Sanskrit (in 2005),
Kannada and Telugu (in 2008).
In 2005, Sanskrit, which already had special status in Article 351 of the Constitution of India as the primary source language for the development of the official standard of Hindi, was also declared to be a classical language. This was followed by similar declarations for Kannada and Telugu in 2008, based on the recommendation of a committee of linguistic experts constituted by the Ministry of Culture, Government of India.