The Hindu system of rigid hereditary social classes, especially in India. There are four castes: Brahmins, Ksatriyas, Vaisyas and Sudras, plus the out-castes or Dalits, who are not part of the caste system. Within each caste, there are many sub-castes or "Jati"See also: Brahmin, Dalit, Jati, Kshatriya, Outcaste, Sub-caste, Sudra, Vaishya, Varna