Vyasa composed the Mahabharata. The narration that we hear is by Ugrasravas who in turn heard Vaisampayana narrate the story to Janamejaya during Sarpa Yajna. Ugrasravas narrated the story at Naimisaranya at the request of Kulapati Saunaka.

Ugrasravas, son of Lomaharsana is also called Suta Pouranika. They belong to the Suta clan. Sautis are story tellers. Sautis are very talented storytellers who can make the story gripping. They also narrate the moral lessons in the stories. They normally tell stories to Kings.

Naimisaranya is near Ayodhya and Lucknow in present day Uttar Pradesh. The Kulapati Saunaka was conducting the 12 year long Satra Yajna. Satra Yajna is known for abundant food distribution. The Yajna aims to satisfy all creatures, not just Devatas. There are several kartas for the Yajna since it is a long and big  Yajna. The Ritwik who conducts the Satra Yajna is also the Yajamana.

Kulapati is a person who has hosted more than 10,000 Rishis and their families. Saunaka was the Kulapati and he conducted the Satra Yajna which was visited by Ugrashravas Sauti.

Vaisampayana heard Mahabharata from Vyasa (1st). Ugrashravas heard the narration of Vaisampayana to Janamejaya (2nd). Saunaka and other Rishis heard it from Ugrashravas (3rd). This is the version that we hear and read.

The 18 parvas can be organised into four groups. The first 5 parvas are called Aadhya Panchakam or the first 5. The next 5 parvas are called Yuddha Panchakam. The next three parvas are called Shanti Trayam. The last five parvas are called Andhya Panchakam. There are more than 2300 chapters which are further grouped into upa parvas.

Vyasa was thinking of how to teach or narrate Mahabharata after his disciples. During this thought he remembered Brahma. Brahma appeared at the same time in front of Vyasa. Vyasa mentioned to him that he has thought of the greatest work that contains everything in the Vedas. But he is confused about who can write it down. Brahma tells him that nobody on earth can write this and asks him to think of Vigneshwara. When Vyasa thought of Vigneshwara he immediately appeared before Vyasa.

Koota Slokas are slokas that are difficult to understand. When Vyasa requested Vinayaka to write down Mahabharata, Vinayaka agreed with one condition. He said that his quill will write continuously and Vyasa also has to narrate continuously without stopping. If he stops, the quill will stop and will not restart. Vyasa agreed but imposed his own condition. He said Vinayaka can only write down the slokas that he understands. Thus, to gain time, Vyasa composed some difficult slokas. As Vinayaka paused to understand, Vyasa gained time to compose further slokas. Mahabharata is believed to contain more than 8000 Koota Slokas.

In latter stories of Mahabharata it is mentioned that Vinayaka broke off his tusk and used it as a pen. This story is not in original Mahabharata. However, this is used to explain how Mahabharata is a story of sacrifice. The tusk is a very valuable body part for an elephant. Since Vinayaka broke his tusk and used it as a pen, it signifies the sacrifice that he made to write Mahabharata.

Vyasa composed many versions of Mahabharata. He composed a total of 60 lakh slokas out of which 30 lakhs were recited to Devatas. Another 15 lakh slokas were recited to Pitrus and another 14 lakh slokas were recited to Gandharvas and Rakshasas. The remaining 1 lakh slokas were recited for humans and this is the Mahabharata that we read and hear.

Anukramanika is the first Adhyaya of Mahabharata. It has 274 verses. The verses 110 to 274 are a concise summary of Mahabharata. In these verses Drtarashtra tells Sanjaya that he always knew that his sons will lose the war. Drtarashtra recounts a key event of Mahabharata in each of these slokas. At the start of each of these slokas he laments to Sanjaya that when this event happened he knew that his sons will lose.