Okay kiddo, so imagine a campervan hire agency is like a big toy store for grown-ups who love to go on adventures. You know how you have your toy cars and dolls that you like to play with and take with you on trips? Well, for grown-ups, they have something called a campervan which is like a big car that you can sleep in!
But not everyone owns a campervan, just like how not everyone owns all of the toys they want to play with. So these agencies have lots of different campervans (or toys) that people can come and borrow for a little while.
Now, when someone wants to borrow a campervan for their adventure, they go to the agency and pick out the one they want. But they can't just take it home right away - they have to pay for it first! This is like how grown-ups have to pay for their groceries before they can take them home.
Once they've paid, they're allowed to take the campervan for their adventure! But here's the thing: they have to promise to take good care of it and bring it back clean and undamaged. Just like how you have to promise to take good care of your toys and bring them back to the toy store the way you found them.
When they're done with their adventure, they bring the campervan back to the agency and say goodbye to it. But if they had a really good time, they might want to borrow another one again someday!