The occasion is also rendered Vira Ashtami to mark the usage of arms or martial arts on this day.
It falls on bright lunar fortnight Ashtami tithi of Ashvina month according to the Hindu calendar.
It is believed in some regions, the goddess Chamunda appeared on this day from the forehead of Durga and annihilated Chanda and Munda, and Raktabija (the asuras (demons) who were associates of Mahishasura).
The Ashta Shakti worshipped during Durga Puja are Brahmani, Maheswari, Kaumari, Vaishnavi, Varahi, Narasinghi, Indrani and Chamunda.
A tradition associated with Durga Ashtami that originated in North India is to honour the kanyaka (young girls) with a ritual called the Kanya Puja.