The Indian caste system is a system of social stratification and social restriction in India in which communities are defined by thousands of endogamous hereditary groups called Jātis.

The caste system played an influential role in shaping economic activities,[16] where it functioned much like medieval European guilds, ensuring the division of labour, providing for the training of apprentices, development and protection of intellectual property and, in some cases, allowing manufacturers to achieve narrow specialisation and global monopoly. For instance, producing each variety of cloth was the specialty of a particular sub-caste, but the weavers of Dhaka produced the renowned muslin that was in demand internationally. It has been suggested that the majority of people tend to be comfortable in stratified endogamous groups, as they have always been, since ancient times.[17]

There have been challenges to the caste system from the time of Buddha,[25] Mahavira and Makkhali Gosala. Opposition to the system of varṇa is regularly asserted in the Yoga Upaniṣad-s and is a constant feature of Cīna-ācāra tantrism, a Chinese-derived movement in Asom; both date to the medieval era. The Nātha system, which was founded by Matsya-indra Nātha and Go-rakṣa Nātha in the same era and spread throughout India, has likewise been consistently opposed to the system of varna.