Okay kiddo, do you know what it means when something is broken and needs to be fixed? Design for repair is about making things easier to fix when they're broken, so that we don't always have to throw them away and buy new ones.
Let's say you have a toy car that stops working. Design for repair means that the people who made the toy car made it so that you can take it apart easily to see what's wrong. They might have also labeled the different pieces of the toy car to show you where they go and how they fit together.
This way, you or an adult can fix the toy car instead of throwing it away and buying a new one. It's better for the environment because we don't create as much waste when we can fix things instead of always buying new ones.
Design for repair is important for other things too, like appliances, furniture, and even your clothes. When things are designed well for repair, it saves time and money, and it's better for our planet.