The Shudra is the lowest of the four traditional castes, or varnas, of India and traditionally includes artisans and laborers. According to the Rig veda, the main function of the Shudra is to serve the other three castes.
Under the caste system, the Shudras have fewer privileges and rights than the upper castes—the Brahmins, Kshatriyas and Vaishyas. A large part of the Indian population is comprised of the Shudras. It is possible for an individual to emerge from the Shudra caste and claim Kshatriya or Vaishya status. As they are a low social class, the Shudra cannot perform the upanayana, an initiatory rite.