Upanayana is a Hindu educational sacrament, one of the traditional saṃskāras or rites of passage that marked the acceptance of a student by a preceptor, such as a guru or acharya, and an individual's initiation into a school in Hinduism. Some traditions consider the ceremony as a spiritual rebirth for the child or future dvija, twice born. It signifies the acquisition of the knowledge of and the start of a new and disciplined life as a brahmāchārya. The Upanayanam ceremony is arguably the most important rite for Brāhmaṇa, Kṣatriya, and Vaiśya males, ensuring their rights with responsibilities and signifying their advent into adulthood.