Have you ever borrowed money? Of course you have! Whether we hit our parents up for a few bucks to buy candy as children or asked the bank for a mortgage, most of us have borrowed money at some point in our lives.
Just as people need money, so do companies and governments. A company needs funds to expand into new markets, while governments need money for everything from infrastructure to social programs. The problem large organizations run into is that they typically need far more money than the average bank can provide. The solution is to raise money by issuing bonds (or other debt instruments) to a public market. Thousands of investors then each lend a portion of the capital needed. Really, a bond is nothing more than a loan for which you are the lender. The organization that sells a bond is known as the issuer. You can think of a bond as an IOU given by a borrower (the issuer) to a lender (the investor).
Of course, nobody would loan his or her hard-earned money for nothing. The issuer of a bond must pay the investor something extra for the privilege of using his or her money. This "extra" comes in the form of interest payments, which are made at a predetermined rate and schedule. The interest rate is often referred to as the coupon. The date on which the issuer has to repay the amount borrowed (known as face value) is called the maturity date. Bonds are known as fixed-income securities because you know the exact amount of cash you'll get back if you hold the security until maturity.
