Poonal, technically known as ‘Yajnasoothram’ or ‘Yajnopaveetham’, is a sacred thread worn by the Brahmin
and certain other communities such as Kshatriya
. It is worn around the trunk of their body over the left shoulder and under the right arm, and represents clothing.
In South India, boys start wearing poonal with Upanayanam. Every year on Aavani Avittam, it is changed anew, along with the chanting of mantras.