According to Hinduism, threads are used for different purposes. There are several different types of threads and tying them in different parts of the body are associated with specific rituals or festivals.
Kalava (Sacred Thread) During Puja
Mauli or Kalava, a red cotton string or thread that sometimes has a few yellow colored elements is a sacred thread. As the thread is considered to be an integral part of any puja, it is tied by the priests on the wrists of the people before the beginning of a religious ceremony or havan.
Instructions To Tie Kalava
it is tied on the right hand of men and married women and on the left hand of unmarried girls by reciting mantras.
Significance Of Kalava
According to popular belief the sanctified red thread with the blessings of deities will protect a person from disease, enemies and other dangers.
Thread During Vat Savitri
Vat Savitri is a celebration, when married omen pray for the prosperity and longevity of their husbands by tying threads around a Vaṭ (Banyan Tree) almost 108 times. It honors Savitri, the legendary wife who rescued her husband’s soul from the King Of Death, Yama.
As Banyan tree is symbolic for good health and long life, women by walking around the tree 108 times, contemplate on these matters and pray for their husbands. A single thread may be weak, but, when it is wound 108 times around the trunk, it becomes strong. It is no longer so fragile and no longer easy to break.
Tying Thread On Raksha Bandhan
Tying of a mauli or a red silk thread (rakhi) by a sister on a brother’s right wrist is called Raksha Bandhan (Bond of prtection). This symbolizes the sister’s love and prayers for her brother’s well-being and the brother’s lifelong vow to protect her.
Read here about Raksha Bandhan