Okay, so imagine you and your friend have a toy that you don't agree on how to share. Maybe you want to play with it all day, but your friend only wants to play with it for a little while. You can't come to an agreement on your own, so you ask a grown-up to help you decide who gets to play with the toy and for how long.
The Court of Chancery of the County Palatine of Durham and Sadberge was like that grown-up. But instead of toys, people would come to the Court when they had disagreements about property, money, or other important things. The Court would listen to both sides and then make a decision on how to solve the problem.
But this wasn't just any Court - it was like a special Court that only existed in the area around Durham and Sadberge. This area was called a County Palatine, which means it had its own laws and was sort of like an independent state within England. Think of it like a mini-country inside a bigger country.
The Court of Chancery was really important because it helped people resolve their disputes without having to resort to violence or breaking the law. And because it was part of the County Palatine, it followed its own unique rules and procedures that were different from other Courts in England.