Durga

Durga Devi is fierce goddess of destruction, power and justice. She is called Mahishasura Mardini since she killed the fierce Rakshasa, Mahishasura. She is the most powerful goddess and is considered as 'mother'. She is one of the Tridevi.

History
Durga wasn't actually born but was created by gods. When the buffalo demon, Mahishasura, started torturing the gods. They created a powerful woman, gave her ten hands and a lot of weapons. She was created by Vishnu, Shiva and Brahma and the other gods. They also gave her powers and energy because of which she is called Shakti.

Navadurga
Navadurga is the Avatar of Durga where 9 avatars of Durga is seen.