A backstory is like a really long story that explains everything about a person or a thing. Imagine if you were reading a book and you learned all about a character's life before the story started. That's their backstory!
Let’s say you have a toy car. You know what it looks like and how it moves when you play with it, but it didn't always look like this. It had a different shape and color and moved differently before it became the toy car you have now. The story of how it changed and became what it is now is its backstory.
Backstories help us understand how someone or something became what they are today. It's like learning the whole history of a person or thing so that we can understand who they really are. It can also help us predict what they might do in the future because we know what their past experiences were like. It’s just like when you learn about your friend’s favorite foods, you can predict what they might want to eat for lunch. So, that’s what a backstory is!