The festival of Diwali in India is celebrated over a period of five days. The first day of Diwali is called Dhanvantari Triyodashi or Dhanteras. On this day, Lord Dhanwantari, the god of medicine, came out of the ocean with the science of Ayurveda for mankind. The second day of Diwali is called Naraka Chaturdashi. The third day is for Lakshmi Puja. The fourth day is Govardhan Puja, the day when Lord Krishna asked the people of Vrindavan to pray to Giri Govardhan, the hill, instead of Indra. The fifth day is dedicated to brothers and sisters and is celebrated as Bhai Dooj. It is based on the belief that in the Vedic Era, Lord of Death, Yama, once visited his sister Yamuna. He gave her a boon that whoever would visit her sister on this day, would be liberated of all his sins and will achieve moksha.
The most popularly known story of Diwali is that of the return of Lord Ram to Ayodhya with his wife Sita and younger brother Lakshman after killing the Demon King, Ravana in Lanka. The people of Ayodhya lined the streets and their homes with oil wicks in clay lamps to welcomed them. Since that day, Diwali is celebrated with great pomp and show as a remembrance.