The annual percentage rate, or APR, is the sum of the interest rate and any other fees that a lender may impose on borrowers. APR provides you with a complete picture of what you will actually pay, as opposed to a standard interest rate that only displays the cost of the loan. It is computed as a single annualized percentage that includes the interest rate, processing fees, and other charges. APR is important because it enables fair comparison of various credit cards or loans; two offers may have the same interest rate, but the one with a higher APR will end up costing more in total.