The word Puranam means that which was composed firstpurvasmin bhutam puranam. There are eighteen Mahapuranams- (Vide This work, III. Vi. 20) They form three groups, namely,sattvika, rajasaandtamasa. The six, Matsya, Kurma, Linga, Siva, Skanda and Agni aretamasaPuranams. The six Brahmanda, Brahmavaivarta, Markandeya, Bhavirya, Vamana, and Brahma arerajasaPuranam-s and the six Visnu, Naradiya, Bhagavata, Garuda, Padma and Varaha aresattvikaPuranam-s. This classification of the Puranams and other works according to the qualities which prevail in them is found in the Uttara Khanda of Padma Puranam.