Brahma, Vishnu and Maheshwara comprise of the Hindu Trinity. Brahma is the creator; Vishnu, the preserver while Maheshwara is the destroyer. Maheshwara's image is that of a tiger skin clad sage, bare bodied and who has a third eye on his forehead.
Once Maheshwara opened his third eye and from it emitted a raging fire furious enough to destroy the three worlds. There was complete panic everywhere and Gods and Demons alike ran for protection. However Saraswati, the image of peace and simplicity, remained calm, 'this fire will only burn that which is unholy and improper' she said.
She then took the form of a river whose water body absorbed the deadly fire and transported it to the bottom of the ocean. The fiery energy there took the form of a fire emitting mare called Badavagni. 'As long as there is purity of soul in mortals and wisdom at play, the creature will remain dormant at the bottom of the ocean. The day, wisdom is abandoned and the distinction between good and wicked is lost, the fire will destroy mankind so said Saraswati.
The Gods and Demons saluted Saraswati and thanked her profusely for having the wisdom to realize the ultimate truth of Shiva or Maheshwara's fury.
Brahma was once again amazed at Saraswati's wisdom and from then on, she came to be known by the name Sharda, one who leads the ignorant from darkness to the light of knowledge; one who is the pilot of the journey from ignorance to enlightenment.