Goddess Durga and Goddess Bhagavati are manifestations of Goddess Shakti. The Goddess Durga form of Mother Goddess is worshipped throughout
. The Bhagavathi form is worshipped mainly in Kerala and few temples in Karnataka, Maharashtra, Tamil Nadu, Andhra Pradesh and India Goa. There is a difference between Durga and Bhagavathi worship.
Goddess Durga is fierce form Goddess Shakti that appears to quell Adharma and restore Dharma. Goddess Bhagavati is a peaceful form of Goddess Shakti. The dominating aspect of Bhagavati is motherly affection.
Goddess Bhagavati becomes fierce like Durga, Kali and Chamunda when her children are harassed or attacked by those treading the path of Adharma.
So you will find fierce form of Goddess Bhagavati being propitiated during festivals and special occasions. On all other occasion, she is the caring and compassionate mother.