How the caste system evolve? is is democratic or not?

The caste system evolved from a social classification/stratification to keep peace and order in the society into a racial and social discrimination. I think it's not democratic because They based on culture and belief. The social class will be inherited by their offspring and there is no possibility for them to go higher in class. Their social classification will be permanent and only karma (as they say it) will declare a person's class. Special treatments, rights , freebies and privileges were exclusive to those of high class.
It is very unjust and unfair, it is better to have a conspicuous social stratification than to have the caste system of India.