The religious significance of Diwali varies regionally within India. One tradition links the festival to legends in the Hindu epic Ramayana, where Diwali is the day Rama, Sita, Lakshman and Hanuman reached Ayodhya after a period of 14 years in exile after Rama’s army of good defeated demon king Ravana’s army of evil.

Many of these stories are about the triumph of good over evil. In northern India, a common tale associated with Diwali is about King Rama, one of the incarnations of the god Vishnu. When an evil king in Lanka (which some people associate with Sri Lanka) captures Rama’s wife Sita, he “builds up an army of monkeys” to rescue her, Jain says.

The monkeys “build a bridge over from India to Sri Lanka, and they invade Sri Lanka and free Sita and kill that evil king,” he says. As Rama and Sita return to the north, “millions of lights are spread out across the city Ayodhya just to help them come back home, just to welcome them.” Lighting lamps has long been one of the ways that Hindus celebrate Diwali.

In the south, Diwali is popularly linked to a story about the Hindu god Krishna, a different incarnation of Vishnu, in which he frees some 16,000 women from another evil king. In the western state of Gujarat, the New Year coincides with Diwali (there are multiple New Years throughout India), and Diwali is associated with asking the goddess Lakshmi for prosperity in the coming year. During the festival, many celebrants exchange gifts and coins.

Other religions like Buddhism, Jainism, and Sikhism use Diwali to mark important events in their histories, too. Professor Jain says that while Diwali is a religious holiday, it’s also somewhat of a national holiday in India. Comparing it to Christmas in the United States, he points out that many non-Christians in America still buy a Christmas tree and give each other gifts.