Okay kiddo, so imagine a bunch of magnets. When you hold two magnets close to each other, they stick together, right? That's because they're attracted to each other.
Now let's say we have two different types of magnets, let's call them A and B. Sometimes A and B will stick together, but sometimes they won't. It depends on how strong their attraction is.
The binding coefficient is a number that tells us how strong the attraction is between A and B. If the binding coefficient is really high, that means A and B stick together really well. If the binding coefficient is really low, that means they don't stick together very well.
Scientists use binding coefficients to help them understand how different molecules in our body interact with each other. They can use these numbers to predict if two molecules will stick together or not.
So basically, the binding coefficient is like a measure of how much two things like each other and want to stick together. Simple enough, huh?