Navratri or Navratra iteslf means nine days. Its the festival of worshipping Goddess Durga Mata in her nine swarups. This year in 2008 Navratri ( the second Navratri of the year) is from 30th September 2008 to 9th October 2008. Each day of Navatri represents one of the following nine swarups of Durga Mata.
Day 1 - Mata Shailputri
"Shail" means mountains and "putri" means daughter. Ma Shailputri means daughter of mountains and this swarup refers to Goddess Parvati who was the Daughter of King Himavan
(the King of the mountains). Ma Shailputri is depicted with two hands, one with a trident and the other with a lotus. She is seated upon a bull. She is believed to be an embodiment of the power of Brahma, Vishnu and Shiva. In her previous incarnation, Shailputri is believed to be Sati, the daughter of Daksha and the wife of Lord Shiva. Once Daksha had organized a big Yagna and did not invite Shiva. But Sati being obstinate, reached there. Thereupon Daksha insulted Shiva. Sati could not tolerate the insult of husband and burnt herself in the fire of Yagna. In other birth she became the daughter of Himavan, the king of the Himalayas in the name of Parvati - Hemvati and got married with Shiva once again. Mata Shailputri or Ma Parvati can be worshipped at any temple of Shivji where her deity is always present next to her consort God Shiva.
Day 2 - Mata Brahmacharini
She is the one who practices devout austerity. Filled with bliss and happiness, she is the way to emancipation - Moksha.
The second Durga Shakti is Brahamcharini. Brahma that is who observes penance(tapa) and good conduct. She is depicted with prayer beads in her right hand and Kamandal in left hand. Legend states that in a previous birth she was Parvati /Hemavati the daughter of Himvan. Once when she was busy in games with her friends,Naradaji came to see her and on reading her hand/palm-lines Narad Muni stated that, "You will get married with a naked-terrible 'Bhole baba' who was with you in the form of Sati, the daughter of Daksh in previous birth. But now you have to perform penance for him." There upon Parvati told her mother Menaka that she would marry none except Shambhu, otherwise she would remain unmarried. Saying this she went to observe penance. That is why her name is famous as tapacharini - Brahmacharini. From that time her name Uma also became familiar.
‘Brahma’ here refers to the meditative aspect of Brahmacharini and is always depicted as pious women or Sannyasin. She is also worshipped as goddess Tara and is associated with the pious form of Goddess Shakti. She is believed to be that aspect of Mother Goddess, which was present in Sati and Goddess Parvati, when they both did intense austerities to get Lord Shiva as husband. During the penance Mata Parvati did in order to gain Lord Shivji as her consort for thousands of yrs. without eating even leaves she penance so she was called 'Aparna'. Seeing her body her mother uttered U-ma and so she is also called 'Uma'. Her worship increases sacrifice,good deeds & restraint in humans. Rudraksha is her most adorned ornament.
In some regions, Goddess Chamunda swarup of Durga is worshiped on the second day of Navratri. In this form she is believed to have killed the demons Chanda and Munda.
Day 3 - Mata Chandraghanta
Chandraghanta Ma is known and named Chandraghanta or Chandra-Khanda for the semi-circular moon (Chandra) which appears like a bell (Ghanta) on her forehead. Durga is also worshipped as Ashtamukhi and Shorashi in different parts of India on this day. She is depicted as having three eyes and ten hands holding with ten types of swords - etc. weapons and arrows etc. and is seated on a lion (in some photos on a tiger) and shown as ready for going to war. She is the image of bravery. The frightful sound of her bell terrifies all villains and demonic incarnations. She is also the giver of supreme knowledge and bliss and is depicted as having golden skin with the half circular moon on her forehead, glowing. Her ten hands hold .........
She is worshipped in this form in Kanchipuram (Tamil Nadu) India.Srisailam Devasthanam also is a temple of Ma Chandraghanta.
A very popular legend associated with Ma Chandraghanta is the story of Raja Harischandra her devotee.
Day 4 - Mata Kushmanda
On the fourth day Mata Durga is worshipped as her Ma Kushmanda swarup. She is depicted as seated on a lion, and possesses eight arms. She resides in solar systems and represents all knowledge. Seven types of weapons are shown in seven hands and prayer beads €in her right hand. She likes the offerings of "Kumhde." Therefore her name "Kushmanda" has become famous.
She is also known as 'Krishnamanda' and is believed o have created the universe,so she is called as Adi Swarup. She is also called 'Astbhuja'. Worship of Ma Kushmanda brings light into darkness and ignorance, gives true knowledge,destroys ego, disease, sorrow, depression, ignorance. "Kumbh Bhand" means to see cosmic vivacity in Pindi shape or knowledge of cosmic intricacies in human race. The abode of Mata Kushmanda is in Bhimaparvat.
Day 5 - Mata Skandmata
She is the Goddess of Fire. The fifth swarup of Ma Durga is "Skanda Mata". The daughter of Himalaya, after observing penance got married with Shiva. She had a son named "Skanda." Skanda is a leader of the army of Gods. Skanda Mata is a deity of fire. Skanda is seated in her lap. She has three eyes and four hands. She is white and seated on a lotus.
Some also depict her sitting on a lion with her son Skand ( Lord Kartikeya) in her lap with two hands holding lotuses while the other 2 hands respectively display defending and granting gestures. Its said, by the mercy of Ma Skandmata, even the idiot becomes an ocean of knowledge. The great and legendary Sanskrit Scholar Kalidas created his two masterpieces works viz. "Raghuvansh Maha Kavya" and "Meghdoot" by the grace of Ma Skandmata.However some believe Kalidasa was also inspired and blessed by Ma Kushmanda.
Day 6 - Mata Katyayani
The goddess of Vrindavan, she is depicted as having four arms and three eyes, she is seated on a lion. She is the sixth swarup of Ma Durga and is known as Mata Katyayani. The son of "Kat" was "Katya". Rishi Katyayan was born in this "Katya" lineage. Katyayan had observed penance with a desire to get Ma as his daughter. As a result she took birth as a daughter of Katyayan. Therefore her name is "Katyayani" . She killed the demon Mahishasur.
To get Krishna as a husband gopis worship Ma Katryayani in Vraj. So she is established as the Queen of Vraj.
Day 7 - Mata Kaalratri
Any type of fear goes away by her worship. Shubhankari Mata always give 'Subh' good fruits.Day 8 - Mata Mahagauri
She is like an eight-year-old girl. She is intelligent and peaceful, possesses three eyes and four arms, and uses the bull as her vehicle.The Eighth swarup of Ma Durga is Ma "Maha Gauri." She is depicted as fair as a conch, moon and jasmine flowers. Her clothes and ornaments are white and clean. She has three eyes. She rides on bull She has four hands. The above left hand is in "Fearless - Mudra" and lower left hand hold a "Trishul." The above right hand has tambourine and lower right hand is in blessing style. She is calm and peaceful. It is said that when the body of Gauri became dirty due to dust and earth while observing penance, Shiva makes it clean with the waters of Gangas. Then her body became bright like lightening. There fore, she is known as "Maha Gauri" .
She is also worshipped as Ma-Ambaji, Ma-Kalika, Ma-Bahucharaji. Ma Mahagauri can be seen in a temple at Kankhal near pilgrim centre Haridwar, India
The Ninth Swarup of Ma Durga is Mata Siddhidatri. There are eight Siddhis or accomplishments, they are- Anima, Mahima, Garima, Laghima, Prapti, Prakamya, Iishitva & Vashitva. Maha Shakti gives all these Siddhis. It is said in "Devipuran" that the Supreme God Shiv got all these Siddhies by worshipping Maha Shakti. With her gratitude the half body of Shiv has became of Goddess and there fore his name "Ardhanarishvar" has became famous. This swarup is depicted as seated on a lion and has four hands. She is the giver of all forms of accomplishments[Siddhis].As per the Brahmavaivart Purana there are 18 types of achievements which are Anima, Mahima, Garima, Ladhima, Prapti, Prakaamya, Ishitva,Vashitva, Sarvakaamaal, Saadhita, Sarvagynatva, DurShravana, Parkaayapraveshan, VakaSiddhi, Kalpavrushatva, Shrishti, Samharkaransaamarthya, Amaratva, Sarvanyayakatva, Bhavana and Siddhi. Seated upon a lotus, most commonly, with 4 arms, and is the possessor of different siddhis /accomplishments to grant her devotees. Mata Siddhiratri's famous pilgrim centre, is located in Nanda Parvat in the Himalayas.
Thanks to abhilash,subhamoy das who have explained some aspects so well.