Okay kiddo, so convocation of episcopal churches in Europe means that a bunch of churches in Europe that have bishops (important leaders) get together to talk about important things. It's like all the bishops are having a big meeting to discuss what they're doing to help people and share their ideas with each other. They want to make sure they're all working together to do good things for the people in their communities. It's kind of like when you and your friends get together to work on a big project, but these bishops are working on something really important that affects lots of people.