Okay kiddo, imagine you have a really big house with a lot of rooms. You're in charge of cleaning and taking care of the whole house, but some rooms are more important than others.
In a territorial abbacy, it's kind of like that big house, except it's a big area of land with different places that need to be taken care of by a leader or religious figure called an abbot or an abbess. They're like the "housekeeper" of this big area, and they make sure everything is running smoothly.
The leader of the territorial abbacy is responsible for all the people, buildings, and land in that area. They have a lot of power and authority, kind of like a boss.
Instead of being elected, this leader is usually appointed by someone else in power, like a pope or a king. They might also have special rules and rights that other people in the area don't have, like being exempt from paying certain taxes.
So, a territorial abbacy is basically when a leader is given control over a large area of land and they're responsible for taking care of everything in it. It's kind of like being the boss of a really big house, but instead of just cleaning and organizing, the leader has to make sure everything is running smoothly in a big, important region of land.