Basically, the Mahabharata is to India and some other parts of Southeast Asia what the Bible is to countries where a plurality of the inhabitants are Christian: even if you're not a Hindu or not a practicing anything, you know the stories and what they mean.

Just like any American, Christian or not, could give you a pretty good explanation of what Noah's Ark is or what the expression "to bear one's cross" refers to or what Lazarus was famous for, so any Indian knows who Arjuna was and what weapon he was really good with, why it was that a woman named Draupadi was married to five brothers, or why it was significant that both a man and an elephant were named Aswathama.

However, the big difference between the Mahabharata and the Bible is that the Mahabharata is much more fun more of a continuous narrative, like the New Testament, but with sharply defined, if larger than life, characters.

There is a long poetic and philosophical interpolation, the Bhagavad Gita, which is famous in its own right. Edward Teller is supposed to have quoted one translation of it when he witnessed the testing of the atom bomb: "I am become death, the destroyer of worlds."