On the second day of Navratri, Devi Brahmacharini is worshiped After Kushmanda form, Goddess Parvati took birth at the home of Daksha Prajapati. In this form the Goddess Parvati was a great Sati and her unmarried form is worshipped as Goddess Brahmacharini.
On the third day of Navratri, Devi Chandraghanta Goddess Chandraghanta is the married form the Goddess Parvati. After getting married to Lord Shiva Goddess Mahagauri started adorning her forehead with half Chandra and due to which Goddess Parvati was known as Goddess Chandraghanta.
Vishwakarma puja is a celebration of an awesome architect, God Viahwakarma. His architectural art constructed Lord Krishna's holy city Dwarka, Pandavas Maya Sabha and many weapons. It is celebrated in India on 17th of September. This day is celebrated by engineers, Artists, Craftsmen, mechanics, welders, smiths, factory worker etc. Wearing Lord Vishwakarma Rudraksha (17 Mukhi) see more http://www.rudralife.com/Rudraksha/details.php?id=23
On the fourth day of Navratri, Devi Kushmanda is worshipped. after taking form of Siddhidatri, Goddess Parvati started living inside the center of the Sun so that she can liberate energy to the universe. Since then Goddess is known as Kushmanda,and is the Goddess who has the power and capability to live inside the Sun. The glow and radiance of her body is as luminous as that of the Sun.
On the sixth day of Navratri, Devi Katyayani is worshipped. To destroy demon Mahishasura, Goddess Parvati took the form of Goddess Katyayani. It was the most violent form of Goddess Parvati. In this form Goddess Parvati is also known as Warrior Goddess.
On the eight day of Navratri, Devi Mahagauri is Worshipped. According to Hindu mythologies, the Goddess Shailputri at the age of sixteen was extremely beautiful and was blessed with fair complexion. Due to her extreme fair complexion she was known as Goddess Mahagauri.
On the seventh day of Navratri, Devi Kalaratri is worshipped. When the Goddess Parvati removed her outer golden skin to kill demons named Shumbha and Nishumbha, She was known as Goddess Kalaratri. Kalaratri is the fiercest and the most ferocious form of Goddess Parvati.