The eighteen chapters of "भीष्मपर्व" of the Mahabharat contain 700 shlokas which was composed by maharshi Ved Vyas. भगवदगीता contains teaching given by Lord Krishna to Arjun. It explains the principles of knowledge and devotion and reflects the different aspect of Indian culture.
In the battlefield of Kurukshetra, the Kauravas and the Pandavas have gathered to fight battle. When the battle was about to start, Arjun put his bow and arrows aside and decided to quit the battle. In this situation, a conversation takes place between Lord Krishna and Arjun which is known as "श्रीमदभगवदगीता".