The Dandi March was also known as the 'salt' march and was one of the most significant historical movements for India because this is arguably the event that led to India's mass civil disobedience movement. It was called the Dandi March because Gandhi and his followers marched from Sabarmati Ashram in to the village of Dandi.
Remember that during this time the British prohibited India from collecting or selling salt. And in typical British fashion they were forced to buy salt from Britain which had high cost and taxes. The Salt March ended gaining international attention and helped India gain independence from Britain.