Concordat

A concordat is like a big agreement between two important groups, usually a government and a religious group (like a church). They agree on a bunch of things like who's in charge of what, how they are going to work together, what rights and privileges each side has, and how they are going to solve any problems that come up. It's kind of like making a deal with your friend about how you are going to share your toys and play together nicely. But instead of toys, it's about running a whole country together. Concordats are important because they help make sure that everyone gets along and works together to make things better for everyone.