New Delhi, May 27 -- The annual percentage rate (APR) is one of the most crucial terms every credit card user should understand. It represents the annual interest charged on unpaid credit card balances.

Understanding this concept can help credit card users avoid unnecessary debt and manage finances prudently. It can also help improve understanding of credit cards as borrowing tools.

Most lending institutions calculate APR on the outstanding balance if the full bill amount is not paid before the due date. While APR is expressed annually, interest is generally charged daily or monthly on the unpaid amounts.

Do note, credit card interest rates generally range from about 30% to 48% annually, though some cards may charge lower or higher rat...