1. During Holi a bonfire is also lit to symbolise the story of Prahlada and the demoness Holika.
2. Prahlada's evil father asked his sister Holika to carry his son into a fire, believing she was protected from the flames.
3. Vishnu appeared and protected Prahlada; he remained unharmed, while Holika burnt to ashes.
4. Hindus celebrate this, as it is story of good triumphing over evil.