There are many interpretations of this festival, many dedicate it to medicine God Dhanvantri, many spend time worshipping Goddess Lakshmi while many spend it worshipping Lord Yama. There are 3 major folklores related to Dhanteras. While two are a part of Samudra Manthan, the churning of the ocean, the remaining one is related to Lord Yama.
As per the Hindu mythology, Dhanvantri is the God of Medicine and Ayurveda. He is known to be the one who used Ayurveda for the betterment of mankind and to free them from diseases. On the auspicious day of Dhanteras, the God of Ayurveda, Dhanvantri is worshiped for his wisdom and for curing acute and chronic illnesses with Ayurveda.
God Dhanvantri is also considered as a Doctor to Hindu gods as per the ancient Hindu texts. Ancient mythological books also claim that God Dhanvantri took birth through Samudra Manthan with a pot of Amrit in one hand and a book on Ayurveda in the other.
Another significant story is related to Goddess Lakshmi. As per the mythological texts, Goddess Lakshmi also came from the great churning of the ocean and is a mark of wealth, happiness, prosperity, and good fortune. People make rangolis at the main door and illuminate the main entrance of their home with Diyas to create positive vibes in order to attract and welcome Goddess Lakshmi.
The third legend is about a prince who was the son of King Hima, who was expected to die from a snakebite on the 4th day of his marriage as per the prophecy. But the wife of the princess made a pile from gold, silver, and all the metals at the entrance of her house and lit many Diyas, and spent the entire night telling her husband stories and singing songs.
When Lord Yama, the God of death, came in the guise of a serpent he was unable to see anything because of the brightness of Metals and Diyas. Lord Yama then stayed there and left silently the next morning, which is why Dhanteras is also called Yamadeepdaan which means offering earthen lamps to Lord Yama.
In the evening after the sunset, Goddess Lakshmi is worshipped. People recite Dhanteras ki Katha and Diyas are lighted as well as placed outside every door of the house, barring toilets. People believe that the light of Diyas shows the way to Goddess Lakshmi to their home. Tulsi plant is also worshipped in the evening. Apart from that, a paste of vermilion and rice flour is made to make the footprints of Goddess Lakshmi which again is an auspicious symbol and brings wealth and prosperity to the home.
Naivedya is a popular dish that is offered to Goddess Lakshmi and Lord Vishnu. The dish finds its mention in a lot of sacred texts and is prepared using jaggery and dry coriander seeds. Apart from Naivedya, whole wheat halwa (Aate ka halwa) is also made for Goddess Lakshmi in many parts of North India.
Panchamrit is another Prashad that is prepared for Dhanteras Puja. This chilled beverage is made with 5 elements: milk, sugar, honey, curd, and ghee.