The Synoptic Problem is like trying to solve a mystery. The Bible has three books called Matthew, Mark, and Luke. These books tell the same stories about Jesus, but sometimes they have different details or tell things in a different way. The Synoptic Problem is about trying to figure out why this is and how the books are related to each other.
Imagine you and your two friends were at a party and something really exciting happened, like a magician did a cool trick. All of you would probably tell your parents about it later, but each of you might remember different things or tell the story in your own way. Matthew, Mark, and Luke were like your friends at the party, they were all telling the story of Jesus but remembering different things or saying it in their own way.
To solve the Synoptic Problem, scholars look at all the stories that are told in more than one book and see how they are similar and different. They also study things like the language used and the order in which events are told. By studying all of these details, scholars can try to figure out which book came first and how the other books may have borrowed from it.
It's like a big puzzle that people are still trying to solve today. But even if we don't solve the mystery completely, we can still learn a lot from each of the books about Jesus and what he did when he was here on Earth.