Book entry bonds are bonds that are electronically registered to the financial institution acting on behalf of the investor. Actual coupon bonds are rare today because most bonds are not issued in certificate form; rather, they are registered electronically although some bondholders still choose to hold paper certificates.
Why it Matters: As the price of a bond goes up, its yield goes down, and vice versa.
As the name suggests, these are bonds that pay no coupon or interest. The fact that coupon bonds are usually bearer bonds is important, because it means that anyone who presents the coupon to the issuer is entitled to the interest payment regardless of whether that person is the owner of the bond.
It's onward and upward after you master this. There's actually an interesting story behind the terminology employed; why the phrase "bond coupon" has survived into the 21st century. Bond Investing Basics.