Hey there kiddo, so do you know what clay is? It's a type of dirt that is made up of really small particles that can be molded or shaped. Now imagine a big flat board made out of that clay, just like a piece of paper, but it's made out of dirt instead. That's what a clay panel is, a big flat board made out of clay like dirt.
Now, why would someone want to make a panel out of clay? Well, because it's a really good material for certain things like art or building construction. Artists can use the clay panel as a canvas to paint on or sculpt into shapes, because it's durable and can last a long time. Builders can use them for walls or floors because they're strong and resistant to water and fire.
It's not just any kind of clay though, it's a special type that has been processed and fired, which means it's been heated at a really high temperature. This makes the clay hard and strong, so it doesn't break easily. Once it's fired, people can use it for all sorts of things like decoration, protection, or even just to make something look nice.
So there you have it, a clay panel is just a big flat board made out of special clay that is really useful for making things like art or buildings.