What is the traditional Indian system of social hierarchy known as, which is based on the concept of "varna"?

The traditional Indian system of social hierarchy based on the concept of "varna" is known as the caste system. The caste system categorizes society into different groups, traditionally divided into four main varnas:

1. Brahmins: The priestly and scholarly class, responsible for religious rituals and the pursuit of knowledge.
2. Kshatriyas: The warrior and ruler class, tasked with protection and governance.
3. Vaishyas: The merchant and agricultural class, engaged in trade and commerce.
4. Shudras: The laboring class, responsible for serving the above three varnas.

This system has historically dictated the social order and influenced various aspects of Indian life, including occupation, marriage, and social interactions. While it has faced criticism and legal restrictions in modern India, its cultural influence persists in some areas.