Well, kid, the gospels are like really old books that tell the story of Jesus and his teachings. They were written a long, long time ago by some people who wanted to share their stories with the world. But, the thing is, we're not really sure who these people were.
You see, a long time ago people didn't really sign their names on things like we do today. So, we don't have any writing that says "this book was written by John or Matthew or Mark or Luke." Instead, people have sort of guessed who might have written each gospel based on what the story says and what other people from that time period wrote.
Some people think that Matthew, one of Jesus' disciples, wrote the Gospel of Matthew. Others think that Mark, a follower of Peter (another one of Jesus' disciples), wrote the Gospel of Mark. Luke, a friend of Paul (who also became a follower of Jesus), is thought to have written the Gospel of Luke. And, John, another one of Jesus' disciples, probably wrote the Gospel of John.
But, the truth is, we can't really know for sure who wrote each gospel. What's important is that we have these books today so we can learn about Jesus and what he wanted people to know.