The caste system in India is a system of social stratification, social restriction and a basis for affirmative action. Historically, it defined communities into thousands of endogamous hereditary groups called Jātis.

The Jātis were grouped by the Brahminical texts under the four well-known caste categories (the varnas): viz Brahmins, Kshatriyas, Vaishyas, and Shudras Certain people were excluded altogether, ostracized by all other castes and treated as untouchables.