Indians celebrate Diwali as bright petroleum lamps and colorful lights illuminate homes and streets across the country to celebrate the Hindu festival that symbolizes the victory of light over darkness.

Diwali is the most important festival of the year in India and especially for Hindus. It is celebrated across denominations in the world's most populous country and in the diaspora.

For five days starting Thursday, people take part in fireworks, celebrations and prayers. Diwali is derived from the word “Deepavali” which means “a row of lights”. Revelers light rows of traditional clay oil lamps outside their homes to symbolize the victory of light over darkness and knowledge over ignorance.

The dates of the festival are based on the Hindu lunar calendar and usually fall in late October and early November.

The festival brings with it a number of unique traditions that vary depending on the region. What all festivals have in common are the lights, fireworks, feasting on new clothes and praying.

In southern India, many enjoy a warm oil bath early in the morning to symbolize bathing in the holy Ganges River as a form of physical and spiritual cleansing.

In the north, worship of the goddess Lakshmi, who symbolizes wealth and prosperity, is the norm.

Gambling is a popular tradition as it is believed that anyone who gambles during Diwali will achieve success throughout the year. Many people buy gold on the first day of Diwali, known as Dhanteras – an act they believe will bring them good luck.

Setting off fireworks is a treasured tradition, as is the exchange of sweets and gifts among friends and family. Diwali celebrations typically feature rangoli, geometric floral designs painted on the floor with colorful powder.

This year, several northern Indian states, including the capital New Delhi, are introducing partial or complete bans on fireworks to combat rising pollution during Diwali.