Okay kiddo, imagine that you and your friends are playing a game of tag. You all have different ideas about the rules of the game. Some say you can't tag someone on the head, some say you can tag anyone anywhere. It's all very confusing!
Now imagine that your parents decide to gather all of you together to decide on one set of rules that everyone has to follow. This is what en banc means. It's when all the judges in a court come together to decide on a rule or decision that everyone has to follow.
So, when a court hears a case en banc, it means that instead of just a few judges deciding the case, all the judges from that court will come together to decide on the case. It's like a big meeting where they talk about the case and make a decision that everyone has to follow.
This is usually done when the case is really important or controversial and they want to make sure that all the judges have a say in the decision. So, en banc is just a way to make sure that everyone is on the same page and following the same rules.