Shudra is the fourth varna, whose mythological origins are described in the Purusha Sukta of the Rig veda, one of the sacred texts of Hinduism, and later explained in the Manusmṛti. This latter text defines society as comprising four groups, sometimes also called chaturvarna, of which the other three are Brahmins (priests), Kshatriya (those with governing functions) and Vaishya (agriculturalists, cattle rearers and traders). According to this ancient text, the Shudra perform functions of serving the other three varna.