Diwali, or Deepavali, is celebrated differently in north and south India, according to Devdutt Pattanaik, Author, Speaker, Illustrator, and Mythologist.
In north India, Diwali celebrates the return of Ram from Ayodhya.
In south India, Diwali celebrates the defeat of Narakasura by Krishna, with traditions including wives bathing husbands with oil and unguents, and the crushing of a cucumber-like fruit to represent the destruction of Narakasura.
Diwali in north India celebrates the return of Ram from Ayodhya. Diwali, or rather Deepavali, in south India celebrates the defeat of Narakasura by Krishna.
Author's summary: Diwali is celebrated differently in north and south India.