Upanayana is the ceremony of wearing the sacred thread called Yajnopaveetam. When male child attains 5 years, the wearing of the sacred thread Yajnopaveetam, is ceremoniously done. This Sanskar is second birth for child – A spiritual birth. The child is thereafter authorized to perform all rituals. Studies of Vedas begins with the Guru.

The ceremony has six parts: –

Puja: worshipping the Gods,

Havan: sacrifice,

Shiksha: teaching the morality and duties in life,

Bhiksha: begging as a renounced Brahmchari of Gurukula. Teacher’s teaching has made him renounced minded that he has accepted a life of Vairagee,

Diksha: giving the most sacred Gayatri Mantra to the child, and

Blessings: child is bless by all Gods, Goddesses, ancestors, and elders

It is taking the child to the teacher for initiation of formal education. Along with the sacred thread, the hide of the antelope called Krishnajinam is also worn by the boy. The Upanayana ceremony is followed by brahmopadesha – teaching Gayatri mantra to the boy. (Cited in Manusmrti 2.27)