Upanayana (Sanskrit: उपनयन upanayana-) Janai or janeau or poita or Yagnopavita or Bratabandha(Sanskrit: जनै, जनेऊ) is one of the traditional saṃskāras (rites of passage) that marked the acceptance of a student by a guru (teacher or tutor) and an individual's entrance to a school in Hinduism. The tradition is widely discussed in ancient Sanskrit texts of Hinduism and varies regionally. The sacred thread (yagyopavita or janeu) is received by the boy during this ceremony, that he continues wearing from left shoulder to the right crossing the chest thereafter. Generally this ceremony should be done before the age of 16.
Vedic period texts such as the Baudhāyana Grihyasutra encouraged the three members of society to undergo the upanayana, i.e., Brahmins, Kshatriya and Vaishya.