Diwali is a Hindu festival that celebrates the belief that good will always triumph over evil. The word means series of lights and during the festival, houses and shops are decorated with candles and lights.
The date of the festival is calculated according to the position of the moon and is usually in October or November. This means the date of Diwali changes each year and in 2017, the main date this year was October 19.
Find out why Diwali is celebrated by Hindus.
(Clue: It has something to do with the story of Rama and Sita.)