There are two types of payment cards, credit, and debit. They both have different purposes. They way a debit card works is it allows the user to draw on funds than they have put in the cardholder's account, and you cannot go over that amount deposited. Debit cards can be used to withdraw money from cash machines. On the other hand, a credit card is kind of the opposite of a debit card. A credit card allows you to keep buying things up to a certain limit. This isn't your money and essentially you have unlimited money. But... at the end of the month, you have to pay back the bank for all the money you took. If you don't then they put fines and your credit score goes down. Credit cards are useful since they allow you to keep spending money, but debit cards can be better for people who tend to overuse their money so they don't end up in debt. That is the difference between debit and credit cards.