Nine different forms of Devi, worshiped over the nine days.
As the ten-armed Goddess, Goddess Durga presents a radiantly beautiful form that is bewitching to behold. That special form is somehow simultaneously wrathful and benign and transmits profound spiritual teachings in an exacting manner. The nine-day period from the new moon day to the ninth day of Ashvina is considered the most auspicious time of the Hindu Calendar and is hence the most celebrated time of the year as Durga Puja. The nine different forms of Devi are worshiped over the nine days. These are the most popular forms under which she is worshiped:Durga Shailputri (Daughter of Mountain)
She is a daughter of Himalaya and first among nine Durgas. In previous birth she was the daughter of Daksha. Her name was Sati - Bhavani. i.e. 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 Himalaya in the name of Parvati - Hemvati and got married with Shiva. As per Upnishad she had torn and the egotism of Indra, etc. Devtas. Being ashamed they bowed and prayed that, "In fact, thou are Shakti, we all - Brahma, Vishnu and Shiv are capable by getting Shakti from you."Brahmacharini
The second Durga Shakti is Brahamcharini. Brahma that is who observes penance(tapa) and good conduct. Here "Brahma" means "Tapa". The idol of this Goddess is very gorgeous. There is rosary in her right hand and Kamandal in left hand. She is full with merriment. One story is famous about her. In previous birth she was Parvati Hemavati the daughter of Himvan. Once when she was busy in games with her friends. Naradaji came to her and predicted seeing her Palm-lines 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 became familiar.Chandraghanta
The name of third Shakti is Chandraghanta. There is a half-circular moon in her forehead. She is charmful and bright. She is Golden color. She has three eyes and ten hands holding with ten types of swords - etc. weapons and arrows etc. She is seated on Lion and ready for going in war to fight. She is unprecedented image of bravery. The frightful sound of her bell terrifies all the villains, demons and danavas.Kushmanda
Name of fourth Durga is Kushmanda. The Shakti creates egg, ie. Universe by mere laughing .She resides in solar systems. She shines brightly in all the ten directions like Sun. She has eight hands. Seven types of weapons are shining in her seven hands. Rosary is in her right hand. She seems brilliant riding on Lion. She likes the offerings of "Kumhde." Therefore her name "Kushmanda" has become famous.Skanda Mata
Fifth name of 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.Katyayani
Sixth Durga is Katyayani. The son of "Kat" as "Katya". Rishi Katyayan born in this "Katya" lineage. Katyayan had observed penance with a desire to get paramba as his daughter. As a result she took birth as a daughter of Katyayan. Therefore her name is "Katyayani" . She has three eyes and eight hands. These are eight types of weapons missiles in her seven hands. Her vehicle is Lion.Kalratri
Seventh Durga is Kalratri. She is black like night. Durga hairs are unlocked. She has put on necklaces shining like lightening. She has three eyes which are round like universe. Her eyes are bright. Thousands of flames of fire come out while respiring from nose. She rides on Shava (dead body). There is sharp sword in her right hand. Her lower hand is in blessing mood. The burning torch (mashal) is in her left hand and her lower left hand is in fearless style, by which she makes her devotees fearless. Being auspicious she is called "Shubhamkari."Maha Gauri
The Eighth Durga is "Maha Gauri." She is as white as a conch, moon and Jasmine. She is of eight years old. 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 holds "Trishul." The above right hand has tambourine and lower right hand is in blessing style. She is calm and peaceful and exists in peaceful style. 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" .Siddhidatri
Ninth Durga us Siddhidatri. There are eight Siddhis , they are- Anima, Mahima, Garima, Laghima, Prapti, Prakamya, Iishitva & Vashitva. Maha Shakti gives all these Siddhies. 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. The Goddess drives on Lion. She has four hands and looks pleased. This form of Durga is worshiped by all Gods, Rishis-Munis, Siddhas, Yogis, Sadhakas and devotees for attaining the best religious asset.
Images of Different Forms of Durga Devi: http://www.google.com/search?q=Forms+of+Durga&hl=en&client=firefox-a&hs=eUz&rls=org.mozilla:en-US:official&biw=1440&bih=709&prmd=imvnsu&tbm=isch&tbo=u&source=univ&sa=X&ei=392LTqRIxvrhBOn-8awJ&ved=0CIQBELAE