"Nava-ratri" literally means "nine nights." This festival is observed twice a year, once in the beginning of summer and again at the onset of winter. Maa Durga manifests herself in nine form called Navdurga. One of these nine forms of Maa Durga is worshiped every day in Navratri. The first form of Maa Durga known as “Shailputri". To know more watch the video.