Choti Diwali
The day next to Dhanteras and one day before Badi Diwali is called Choti Diwali or small Diwali or 'Naraka Chaturdashi'.
The celebration of Choti Diwali
On Diwali people prefer to stay at home. Choti Diwali is busy time.  People go to their relatives, friends house and give gift gifts, sweets.
Lot of shopping happen on Choti Diwali.  People decorate their house on Choti Diwali. 
The origin of Choti Diwali
Choti Diwali is  known as "Bali Pratipada".  "Pratiprada"  means "below the opponent's foot".  King Bali was a powerful emperor. Due to his immense power God felt that Bali was gaining too much power. Then God Vishnu, disguised as a sage of diminutive proportions and appeared in in Bali's court. At that time King Bali offered sage to fulfil any wish he has. The sage asked for all the land he could cover in 3his  paces. King Bali immediately . God Vishu then  remove disguise and assumed a gigantic form and claimed the world (Mrityuloka), and the heavens (Swargloka) in two paces. To keep his foot down the 3rd time, he asked for King Bali's head. At that time Bali agreed.

 

Then  kingdom of Bali was overthrown.