Okay, so there's this idea called "conciliarism" which means that a group of people get together (like a council or a meeting) to work together and make decisions. It's kind of like how you might have a club meeting and everyone talks about what they want to do next. In history, this was a big deal because some people thought that the Councils should have more power than just one person (like a king or a pope) to make decisions for everyone. They believed that everyone should have a say and be able to vote on important things. It was kind of like having a big group hug and making important decisions together. But not everyone agreed with this and there were big disagreements about who should have the most power. So, people still talk about conciliarism today, and some places still use it to make decisions.