“prepaid credit card” is generally a card that simulates a credit card in it’s practical applications, but does not actually have any credit except for that which is preloaded onto it. In other words, it gives you a credit card number that you can use to buy things, but you have to put money on it like a gift card before you use it, unlike a real credit card where you get billed later for the charges.
Some banks offer prepaid credit cards, but usually they refer to them as “guaranteed credit cards” or something to that effect. Usually “prepaid credit cards” are bought from pharmacies or other gift card retailers, or even stores like Western Union or check-cashing places. To the best of my knowledge, MasterCard, VISA and American Express all offer prepaid credit cards under various different banners.
The biggest advantage to a prepaid credit card is that it allows someone to purchase things on the Internet, in a case where a person either can’t get a credit card due to bad credit score or simply does not want credit. The main disadvantage is that the card cannot be used for things that require deposits, such as hotel reservations, car rentals, and even some gas stations.
These days, they are commonly given as gifts as a sort of “universal gift card.”
A debit card is “prepaid” by definition since it draws funds directly from a bank account.