Can you explain how APR works on a credit card?

APR, or Annual Percentage Rate, on a credit card is the interest rate charged by the card issuer for borrowing money. It is expressed as a percentage and can vary based on factors like the cardholder's creditworthiness and the type of transaction. The APR is applied to any outstanding balance on the card, and if the balance is not paid in full by the due date, interest will be charged on the remaining amount.