Okay, kiddo, let's talk about the 2018 Moscow-Constantinople schism, which is about a split between two groups of religious people called Orthodox Christians.
Imagine two different groups of kids playing together, but they can't agree on the rules of the game. One group thinks they should play a certain way, while the other group thinks they should play differently. Eventually, they get so upset with each other that they decide to split up and play separately.
That's pretty much what happened with the Orthodox Christians in 2018. There are two main groups of Orthodox Christians - one based in Moscow, Russia, and the other based in Constantinople, which is now called Istanbul in Turkey. They used to play together, so to speak, and both followed the same rules for their religion.
But then, the leader of the Constantinople group, called the Patriarch, made a decision that the Moscow group didn't agree with. He said that a church in Ukraine, which had been part of the Moscow group, could now be part of the Constantinople group instead.
The Moscow group felt like this wasn't fair or right, and that the Constantinople group was changing the rules of the game. So, they decided to split up and play separately. They said they wouldn't recognize the authority of the Constantinople Patriarch anymore, and that they would make their own rules for their religion.
It's kind of sad when friends can't agree and end up splitting up, but sometimes that's just how things happen. Hopefully, both groups will be able to find a way to play together again in the future.