It's about the epic adventures in the Avatar world. It likely includes Aang's journey as the Avatar, his mastery of the four elements, and his battles against the Fire Nation. Also, it may cover the relationships between different characters like Katara, Sokka, and Zuko.
Avatar: The Last Airbender is indeed an original story. It has its own distinct style and narrative that sets it apart. The combination of elements like bending powers, diverse characters, and complex story arcs make it a one-of-a-kind creation.
Definitely not real. It's a fantasy world crafted with unique characters and magical elements that exist only in the realm of imagination and storytelling.