The word Durga (दुर्गा) literally means “impassable”, “invincible, unassailable”. It is related to the word Durg (दुर्ग) which means “fortress, something difficult to defeat or pass”. Durga is derived from the roots dur (difficult) and gam (pass, go through), in other words, Durga means “beyond defeat”. Durga is an aspect of the most powerful goddess or the Devi. She is regarded as the most powerful warrior goddess, as she defeated Mahishasura, a powerful demon. She is associated with protection, motherhood, war, and destruction.
Durga (Shakti) – the Goddess of Power or Strength, is perhaps the most important female Goddess. She is a multi-dimensional Goddess, with many names, many personas, and many facets. As Mahishasuramardini or Shakti, she is the destroyer of evil – with her ten mighty arms carrying lethal weapons she triumphantly slays the demon Mahishasura. As Sati, beloved daughter of King Daksha and Queen Menaka she gives up a kingdom and earns her father’s wrath. As Kali, she turns black as the night and omnipotent, terrible in rage and fury, with just a string of skulls as her garland and her only garb. As Parvati, she is serene, the pretty consort of Lord Shiva by his side in the snowy peaks of the Kailash mountain. She is Bhawani, symbol of life. She is Sati, the object of death. She is Basanti, the heralder of springtime. She is also Amba, Jagadhatri, Tara, Ambika, Annapurna.
Durga, through all her forms, encompasses the essence of salvation and sacrifice. She is the mother of bounty and wealth, as also of beauty and knowledge, for her daughters are Lakshmi and Saraswati (Hindu goddesses of wealth and knowledge, respectively).
According to a narrative in the Devi Mahatmya, Durga was created as a warrior goddess to fight an asura named Mahishasura. He had unleashed a reign of terror on earth, heaven and the nether worlds, and he could not be defeated by any man or god, anywhere. The gods went to Brahma, who had given Mahishasura the power not to be defeated by a man, but Brahma could do nothing. The gods then went to Vaikuntha-the place where Vishnu lay on Ananta Naag. They found both Vishnu and Shiva, and Brahma related the reign of terror Mahishasur had unleashed on the three worlds. Hearing this Vishnu, Shiva and all of the gods became very angry and beams of fierce light emerged from their bodies. The blinding sea of light met at the ashram of a priest named Katyayan and Durga emerged from this pool of light. The goddess Durga took the name Katyaayani from the priest and emerged from the sea of light. She introduced herself in the language of the Rig-Veda, saying she was the form of the supreme Brahman who had created all the gods. Now she had come to fight the demon to save the gods. The Great Goddess Durga was born from the energies of the male divinities when the gods lost the long drawn-out battle with the asuras (demons). All the energies of the gods united and became supernova, throwing out flames in all directions. Then that unique light, pervading the Three Worlds with its luster, combined into one, and became a female form.
It is found in the Markandeya Puran that Devi Durga was worshipped for the first time by king Suratha who was born in the Kshatriya clan during the period of second Manu. There are many incarnations of Durga: Kali, Bhagvati, Bhavani, Ambika, Lalita, Gauri, Kandalini, Java, Rajeswari, et al.