Hey kiddo! Have you ever heard of marriage? Well, sometimes people get married but later on they realize that their marriage wasn't really performed in the right way. In some cases, the church decides that this marriage should have never happened and they declare it "null" or "void".
Pope Francis recently made some changes to the way this process happens. Previously, it could be a really long and complicated process to have an investigation called a "nullity trial" so that the church could make this decision. But now, Pope Francis has made it a lot easier and quicker for people to go through this process.
The pope wants to help people who are going through a tough time in their marriage, and he hopes that these changes will be a way to show that the church cares about their feelings and wants to help them. So, he made it so that this process is more accessible and affordable for people who need it.
Basically, the church just wants to make sure that people have the best chance possible for a happy and healthy marriage. And if they find that a marriage wasn't actually valid, then that means the couple is free to move on and find happiness in other ways.