What is "dhanvantari"

Dhanvantari is an avatar of Vishnu in Hinduism. He appears in the Vedas and Puranas as the physician of the gods ( devas), and the god of Ayurveda. It is common practice in Hinduism for worshipers to pray to Dhanvantari seeking his blessings for sound health for themselves and/or others, especially on Dhanteras.