Please note that credit cards have two main types:
- Credit cards
- Debit card
Debit cards are usually issued by a financial institution (banks), and therefore are using their holder's immediate available balance. Once a charge was completed successfully, the funds are wired from the issuer to the merchant, if there are no funds in the bank account, the customer can not be charged (in opposed to credit card with credit line).
Credit cards use their holders' line of credit, granted by their card issuer company. When a cardholder attempts to use his card, the acquirer, that represent the merchant's account, check if the cardholder has sufficient funds. Assuming there is, the funds are then wired from the holder's line of credit, thru the issuer, the credit company, the acquirer to the merchant.
There are more card types available around the world. Should you consider to accept and process them, please review the terms and conditions with your provider(s) first.