Deviji is synonym to Shakti(power).Mahish-Asur was a demon who was Deviji's Deciple.But he become arrogant and started troubling  Gods and Rishi's along with other demons like Shumb, Nishumb .Then all the God's collectively worshipped Goddess Durga and sought her help.   Goddess Durga got pleased and assured them help and also told them how to worshipp her and keep fasts.

She Killed Mahishasur .Mahish in Hindi means Buffalow and Asur means demon.That is why in Deviji's photographs when she is in her rudhra(angry)form,she is seen killing a buffalo.She killed him in Mysore which has acquired that name drom From Mahishasur .From that day Devi Navratra festival is celebrated every six month.

On the day of Ashtami , Parvati, daughter of King of Mountains, was born and on Nauami Shri Ram Chandra incarnated, that is why it is also called Ram-Naumi.

Navratra comes twice a year. One comes after Holi,somewhere in March-April, which in Chait ke deviya or guddi parwa and the second before Dussehra i.e. in October which is kunwar ki deviya.

From this day Deviji's worshipping and fasts starts.