A charge card requires you to pay the full balance every statement cycle. A credit card lets you carry a balance — at interest.

There’s no universal right number. The optimal number of credit cards depends on your credit score goals, spending habits, and ability to manage payments without missing one.

A balance transfer moves debt from a high-interest card to a new card with a 0% introductory APR — pausing interest for a set period so more of every payment goes toward the principal.

Credit cards touch all five factors that make up your FICO score — and they’re the fastest-moving lever most consumers have. How you use them (or misuse them) shapes your score more than almost any other financial product in your wallet.

A credit card grace period is the window between the close of your billing cycle and your payment due date — typically 21 to 25 days. Pay your full statement balance before the due date, and you owe zero interest on purchases.