The Mahabharata is a very old book from India which has many stories about kings, warriors, and gods. One interesting thing about the Mahabharata is that it has many characters, and some characters have multiple avatars. An avatar is like a different version of a character, with different qualities and powers.
For example, one of the most famous characters in the Mahabharata is Krishna. Krishna is a god who helps the heroes in their battles. But Krishna also has many different avatars, which are like different versions of him. For example, there is the baby Krishna, who is very cute and mischievous. There is also the warrior Krishna, who fights in battles and has powerful weapons.
Another example is the character Arjuna, who is a great warrior in the Mahabharata. Arjuna has an avatar called Nara, who is a wise sage. Nara helps Arjuna in many ways, and gives him advice about how to fight in battles.
Overall, avatars in the Mahabharata are like different versions of characters that have different qualities and powers. They are an important part of the storytelling in the Mahabharata, and add depth to the characters and their journeys.