The Annual Percentage Rate (APR) is a financial term used to represent the total cost of borrowing or the earnings on an investment over a year, accounting for interest rates and any associated fees or costs. It is a standardized way of comparing different financial products, such as loans and credit cards, making it easier for consumers to understand the cost they will incur or return they will get on their investments. Unlike nominal interest rates, APR takes into account other costs such as loan fees, offering a more complete picture of what the borrower is required to pay annually.