According to a Hindu belief, Goddess Durga manifests in nine forms. During Navratri, worshipping these nine forms of Goddess Durga holds a special significance. Each manifestation of Goddess Durga is known by her respective name, governing planet, iconography and mantra for invocation. Following are the nine forms of Goddess Durga that are included in Nav Durga Yatra:
According to a legend described in Chapter 71 in Kashi Khand, Sage Agastya wanted to know from God Kartikeya, how Goddess got the name Durga. Lord Kartikeya narrated a story. Once a demon named Durgasur received special powers after performing rigorous penance for several years and he started torturing all the religious people. He got several worlds (Bhoolok, Swarglok etc.) under his control and created a chaos all over. Seeking a solution to this, all gods and human approached Lord Shiva and asked for almighty’s help. Lord Shiva was aware of the powers of Durgasur and the fact that he is blessed with a boon according to which he cannot be killed by a man. So, Lord Shiva requested Goddess Parvati for the solution. Therefore, Goddess sent her emissary, Goddess Kalratri, along with few other ladies to warn Durgasur and ask him to refrain from tormenting religious people and should return them to their land and go elsewhere otherwise Devi Parvati would certainly slay him. With utter arrogance, Durgasur asked his warriors to capture Goddess Kalratri and imprison her. When the warriors approached her, Goddess Kalratri exhaled jets of fire balls with a roar by which thousands of the warriors were killed. After that, Goddess Kalratri flew to Vindhyanchal mountains where Goddess was residing and narrated the whole incident to her. Soon Durgasur followed Goddess Kalratri to the place where Goddess Adishakti was residing and a fierce war ensued in which Goddess Adishakti divided her powers and took various divine forms to kill the demon. Goddess slaughtered the demon and his army with her supreme powers. Since then, on account of slaying Durgasur, Goddess was known as Goddess Durga.