Before we can go on with the study of money, banking, and financial markets, we must understand exactly what the phrase interest rates means. In this chapter, we see that a concept known as the yield to maturity is the most accurate measure of interest rates; the yield to maturity is what economists mean when they use the term of interest rate. We discuss how the yield to maturity is measured and examine alternative (but less accurate) ways in which interest rates are quoted. We’ll also see that a bond’s interest rate does not necessarily indicate how good an investment the bond is because what it earns (its rate of return) does not necessarily equal its interest rate. Finally, we explore the distinction between real interest rates, which are adjusted for inflation, and nominal interest rates, which are not.