Direct binding is when two things stick together like glue without anything in between. You know how when you want to stick two pieces of paper together, you might use glue or tape to hold them together? That's called indirect binding because there's something in between the two pieces of paper – the glue or tape. But with direct binding, the two things just stick to each other all on their own! It's like magic, but with science! Scientists use direct binding all the time to help them understand how different parts of our body work together, like how different chemicals in our blood stick to each other to help us stay healthy. That's direct binding in action!