Alright kiddo, so the Byzantine Empire was a place a long time ago, kinda like a big kingdom that had lots of people living in it. They had a way of doing things that we call their "economy".
Now, the Byzantine economy was kinda like a big store. Just like when you go to a store to buy things, the people in the Byzantine Empire also traded things to get what they needed. They would trade things like food, clothing, and even money that they made themselves.
But what made the Byzantine economy special was that they had lots and lots of trading going on all over the place. People would travel from far away just to trade with them! And they even had their own big market place where people could buy and sell things.
Now, they were really good at making stuff too. They would make things like silk clothing, fancy pottery, and even weapons for their army. And because they were so good at making things, they would sell it to other places too!
So, in a way, the Byzantine economy was like a big game of trading that everyone played to get what they needed. They were really good at it and that's why they were able to grow big and strong as a kingdom.