Okay, so imagine there's this place called England, where a king or queen is in charge. But sometimes, the king or queen has a son and when they grow up, they might get their own special place to rule over, kind of like a prince's playroom.
One of those special places is called the Duchy of Cornwall, and it belongs to the Prince of Wales, who is the eldest son of the current Queen of England. It's like a big piece of land that has lots of farms and forests and even some castles!
But even though the Prince of Wales is in charge of the Duchy of Cornwall, he can't just do whatever he wants with it. He has to take care of it and use the money he makes from it to help him do his royal duties, like going to fancy events and supporting charities.
So it's kind of like having your own little kingdom to play in, but you have to be responsible and use it to help others too!