Cradle-to-cradle design is a special type of design that thinks about the entire lifecycle of something, from when it's first made to when it's no longer needed. Just like how kids need to think about all the steps they need to take before they go to bed, cradle-to-cradle designers think about all the different parts of something and how they can be reused or recycled.
Imagine you have a toy car that you don't want to play with anymore. You can't just throw it away and leave it on the ground, right? You have to think about where it goes next. One thing you could do is give it to a friend who might want it or donate it to a toy drive. Or, you could take it apart and use the wheels on your skateboard, or the plastic for a birdhouse. That's kind of like what cradle-to-cradle designers do with things like buildings, products, and materials.
Instead of just throwing something away when it's no longer needed, cradle-to-cradle designers try to create things that can be taken apart and used again in different ways, a bit like a puzzle. This means that less energy and resources are used in making new things, which is good for the planet. Plus, it means that things don't have to go to waste, which is good for everyone!