Holika Dahan, also known as Holi bonfire, is a significant ritual observed during the Hindu festival of Holi, which usually takes place on the night before the main Holi festival. The story behind Holika Dahan is deeply rooted in Hindu mythology and varies across different regions of India, but the most popular legend associated with it is the tale of Prahlad and Holika.

In ancient times, there was a demon king named Hiranyakashipu who had obtained a boon from Lord Brahma, making him nearly invincible. With his newfound power, Hiranyakashipu became arrogant and started tormenting the gods. He demanded that everyone worship him instead of the gods. However, his own son, Prahlad, was a devoted follower of Lord Vishnu.

Despite Hiranyakashipu's efforts to dissuade Prahlad from his devotion, Prahlad remained steadfast in his faith. Infuriated by his son's disobedience, Hiranyakashipu enlisted the help of his demoness sister, Holika.

Hiranyakashipu's sister, Holika, had a special boon that made her immune to fire, granted by Lord Brahma.

Hiranyakashipu devised a plan to kill Prahlad by having him sit on Holika's lap in a bonfire. Holika was supposed to emerge unscathed due to her immunity to fire, while Prahlad would perish. However, as the fire blazed, Prahlad prayed to Lord Vishnu for protection, and through the divine intervention, Prahlad survived while Holika was consumed by the flames and perished.

This legend symbolizes the victory of good over evil, faith over arrogance. The ritual of Holika Dahan, where effigies of Holika are burnt, commemorates this event and signifies the triumph of virtue. It also marks the beginning of the Holi festival, a joyous celebration of colors, love, and unity, where people come together to rejoice and forgive.