A credit card is a card issued by a financial institution that allows financing transactions on credit, as its name suggests.
Essentially, the bank advances the capital of the purchases to be paid at a specific time in the future, or in installments if it is a revolving card.
A card with deferred payment works as follows: users make purchases and the money they spend accumulates and is paid out at the beginning of the following month. If there is money in the account to pay for the purchases, nothing happens; but if there is not, the bank will charge an interest rate for the capital lent and not paid back on time.