Ratri means “night” and Nava means “nine”. At Navaratri (“nine nights”), the Lord in the form of the Mother Goddess is worshipped in Her various forms as Durga, Lakshmi and Saraswati. Though the Goddess is one,
She is represented and worshipped in three different aspects. On the first three nights of the festival, Durga is worshipped. On the following three, Lakshmi and then Saraswati Devi on the last three nights. The followingtenth day is called Vijayadasami. Vijaya means “victory”, the victory over our own minds that can come only when we have worshipped these three: Durga, Lakshmi, and Saraswati.
– Swami Tejomayananda