Caffè d'orzo is a special type of coffee that doesn't actually have coffee in it! It's made from a plant called barley, which is roasted and ground up so it looks a lot like coffee.
When you want to make caffè d'orzo, you put a spoonful of the ground barley into a pot or a machine, just like you would with coffee. Then you add hot water and let it brew for a little while.
Once it's ready, you can drink caffè d'orzo just like coffee - you might put some milk or sugar in it if you like, or drink it black. It tastes a little bit like coffee, but not exactly the same because it doesn't have caffeine in it.
So, caffè d'orzo is like a special type of coffee made from barley instead of coffee beans. Kids can drink it too, because it doesn't have any caffeine!