Credit cards are a form of deferred payment that allow cardholders to pay for goods and services based on a promise to pay the balance later. They have several components like the card number, expiration date, and security features. There are different types like standard cards, reward cards, and secured cards for rebuilding credit. Credit cards offer advantages like convenience and cash access but also risks like debt and fraud. Users should take safety precautions like keeping cards secure and reporting lost cards.