In the eastern states of India like Bengal, Bihar and Assam, people celebrate the nine days as Durga festival.The reason why the festival is celebrated for nine days is the Goddess has nine-forms or aspects. In southern India, goddess Saraswathi is also worshipped during the Navaratri.
Your major problem in your life is your animal nature.
It is your inner animal (pasu), which prevents you from knowing the truth of yourself (pati).
It is the most popular epic in the world, and probably the most ancient. Ravana's Effigy Navaratri, the festival of nine nights, is an important festival of Hindus, which is celebrated variously in different parts of India.
It is popular even in countries as far as Thailand, Burma, Tibet, China, and Far Eastern countries. In some states like Uttar Pradesh and Madhya Pradesh, it is celebrated as Ramalila, meaning the play of Rama, to commemorate the victory of Lord Rama against Ravana, the demon king of Lanka.
On the first day, the goddess is invoked by worshipping her clay image. On the tenth day, her image is carried in a great procession and immersed in the waters of a lake, river, canal or ocean.
The festival is celebrated in various parts of India with minor variations.
Whether it is Diwali, Navaratri or Sankranti, people in different parts of India worship different deities and associate different legends to each festival.
While it is difficult to know exactly what happened in the remote past, one probable reason could be that the nine night festival was originally associated with the fertility cults of prehistoric times in the Indian subcontinent.
If you visit North India, in some towns and villages you will see wide open grounds, mostly in the outskirts, where they install large statues of Ravana.
They are usually fierce looking statues, in a battle-ready stance, with one or ten heads, piercing eyes, prominent whiskers, holding a large, curved sword in one hand.