Devi gita constitutes the last ten chapters of the seventh Skandha of the Devi Bhagavatam. In the puranas, one will find several gitas and many mahatmyas. The differences are that in the mahatmya, the glorification of the deity is by recounting the various deeds of the God and offering praise to the divinity. A gita, on the other hand, is a direct revelation of the truth from the disciple, which often includes the manifestation of the cosmic form. While mahatymas emphasize bhakti, gita stresses a balance of bhakti and jnana.
Specifically, we are interested in discussing the Devi gita. To avoid any confusion and also be aware, there are two other devi gitas. The first of which is found in the Kurma purana. This is a conversation with Parvati and Himavan, introduced by Lord Vishnu as Kurma. Goddess Parvati is praised here by 1008 names and She grants him two cosmic visions and instructs him. The other devi gita is found in the Mahabhagavata purana, which actually refers to the conversation of Parvati and Himavan as Parvati Gita. The narrator of this section of the Mahabhagavata Purana is Lord Shiva. However, by Devi gita, we refer only to the gita found in the Devi Bhagavatam.
1 -[The Devi Gita]
2 -[The Devi Gita : The Book]