Design fiction is a way of making up stories and creating objects that aren't real, but could be in the future. Think of it like playing pretend, but instead of just imagining things in your head, you draw pictures or build models to show what your pretend world looks like.
So when people use design fiction, they are imagining what the future might be like, and coming up with things that could exist in that future world. For example, imagine a world where everyone lives in space. Design fiction would help us imagine what kinds of houses, transportation, and technology we might need to make that world possible.
Design fiction is also used to explore ideas that might be too complicated or dangerous to try out in real life. For example, scientists might use design fiction to test out new ideas for space travel before actually building a rocket.
Overall, design fiction helps us imagine and plan for a better future, and it's a lot of fun too!