How does it work debit card or credit card?

A credit card - is a temporary 'loan' from the card company with a 'promise' to pay back the amount spent over a period of time. The card company pays the retailer immediately, and the card-user is billed at the end of the month, with interest charged on the outstanding balance.

A debit card - is a form of electronic 'cash'. The transaction can ONLY be completed if there are already sufficient funds in the bank account that the card is linked to. The amount 'spent' on the card is usually transferred from the users's account the same (or next) working day.