While often used interchangeably, Caste (Jati) and Varna are distinct concepts in Indian sociology. The key differences are:
Number: The Varna scheme is a four-fold classification consisting of only four categories: Brahmin, Kshatriya, Vaishya, and Shudra. In contrast, there are thousands of Jatis (castes) and sub-castes across India.
Origin and Basis: Varna is a theoretical and scriptural model found in ancient texts, originally based on qualities (guna) and occupation (karma). Jati is the actual, complex social reality of groups based strictly on birth (heredity).
Scope: Varna is an all-India framework, a broad, theoretical hierarchy. Jati is a local or regional system of endogamous groups with a specific position in the local hierarchy.
Flexibility: The Varna system was, in its original conception, considered to be somewhat flexible. The Jati system, as it has been practiced, is rigid and determines one's social status for life.