The Mahabharata consists of 18 books, traditionally called parvas.
These eighteen parvas organize the epic’s vast narrative, from the origins and childhood of the Kuru princes through the Kurukshetra War and the Pandavas’ final journey. The opening book is Adi Parva, which covers genealogies, births, education, rivalries, and the early history of the Pandavas and Kauravas.
The central war occupies several books, including Bhishma Parva, Drona Parva, Karna Parva, and Shalya Parva. Bhishma Parva contains the Bhagavad Gita, presented as Krishna’s teaching to Arjuna before the battle begins. The final two books are Mahaprasthanika Parva, concerning the great departure, and Svargarohana Parva, concerning the ascent to heaven.
Readers sometimes encounter a nineteenth title, the Harivamsa. It is traditionally treated as a khila, or supplementary appendix, rather than one of the Mahabharata’s eighteen core parvas. Differences in editions and subdivisions can make the structure look more complicated, but the standard answer to this question is 18.