Maa Durga is the form of Maa AdhyaShakti who represents the life and the existence of the world. She is revered as the supreme energy that is inherent in everything around. Goddess Durga herself represents the Maha Shakti as she is the amalgamation of supreme Goddesses - Lakshmi, Saraswati and Maha Kaali.
Her name –Durga, means ‘ 'The invincible'’.
As per a legend, a demon Mahisasura, pleased Lord Shiva to be bestowed with a boon that no man or god will ever be able to kill him. Mahisasura grew arrogant and started spreading chaos and soon conquered earth and heaven. All the Gods fled to Lord Brahma, Vishnu and Mahesh to seek refuge and relief from the wrath of Mahisasura. The divine trinity – Brahma, Vishnu and Mahesh, combined their powers and created a celestial female form – Durga she engaged in a long battle with Mahisasura who kept on changing forms to deceive. Finally on the ninth day, Durga pierced him with Shiva’s trident and beheaded him with her sword. Hence Maa Durga is also worshipped as a symbol of victory over evil. Vedas describe her as a determined goddess riding a lion with all sorts of weapons in each of her eight hands. The weapons signify the purpose she was created for, to slay Mahisasura. Each of the weaposns in her eight hands depict the power to destroy evil in all the directions.
Maa Durga is worshipped in a different avatar on each day of Navratri, i.e. in the form of Maa Shailputri, Maa Bhramacharini, Maa Chandraghanta, Maa Kushmanda, Skand Mata, Maa Katyayani, Maa Kaalratri, Maa Maha Gauri and Maa Siddidhatri.