Origin story
In entertainment, an origin story is a story that tells how a character or group of characters became the way they are. Very often, it adds to the main story. In comic books, an origin story explains how certain characters got the powers they have (often superpowers), or how they became a hero or villain. When the comic or book is successful and grows older, origin stories are often rewritten and extended.
American comic books show how a superhero or supervillain gains superpowers or transforms into a superhero or villain under certain circumstances.It creates an interest and complexity in the story that fleshes out the character's goals. Adding these narratives gives them a new story that makes their characters look like different characters.
It is the history of characters and other elements that through the situation that exists at the beginning of the main narrative. Even a purely historical work reveals the back story to the audience.[1][2]