Question about PayPal

I need to know if this is possible, under any circumstances.

Let’s say a person pays for something (on a site) using PayPal. They use Paypal only…they don’t, say, put their credit card number on the site itself. They use Paypal, instead, that has a credit card attached to it.
So, is it possible, at all, that the site that they paid for things on could make extra charges somehow? From the PayPal acccount or credit card?

I mean, I thought that PayPal was devised so that one didn’t have to enter their credit card into an unknown site; that they act as the go-between and that the said sites have no way to access the credit card and make additional charges.

Am I wrong? Can a site that you use PayPal on charge more charges? Or is that impossible?
I realize that there could be hidden charges for paying for something. I’m not asking about that.
I’m simply asking the question: Can a site you use PayPal on actually access your credit card or bank account and cause more charges?

No they cannot.

It works just like you think. The merchant doesn’t have access to your details and can’t make a subsequent charge without your say so.
However PayPal does have a “subscription” product so if what you bought on that site was a subscription then you can get charged again when the renewal period comes around. You can cancel subscriptions yourself though.

Thank you, JCorre.
Yes, I knew about the subscription thing…this wasn’t that. This was just a one time buy (and with no hidden fees or “fine print”, I’m certain, because I’ve done this same “one time buy” thing for three months).
But now there are new charges being billed to the same company, so I just was wondering if they were able to see the credit card number somehow and use it.
Thank you for telling me what I already figured.