A cathedral school is like a school that is connected to a really big and special church called a cathedral. In the olden days, kids would go to these schools to learn how to read, write, and do arithmetic, which are things you learn in school too! They would also learn about religion and how to become important people in the church. These schools were often run by really smart and educated people called monks or nuns.
Today, some cathedral schools still exist and are still connected to big and special churches. Some of them are really old and have been around for hundreds of years! While they still teach about religion, they also have regular classes just like any other school. Kids who go to these schools get to be a part of a special community and learn about history and tradition along with their other school subjects.