The yield of a bond to maturity takes into account the price discount from or premium over the face amount. It is greater than the current yield when the bond is selling at a discount and less than the current yield when the bond is selling at a premium. ZERO-COUPON BONDS: A bond sold at a substantial discount which does not pay periodic interest.
The yield if the bond is held to maturity. This is the most frequently used measure of value for a bond. Generally, the calculation is a function of coupon payments, dirty price, and the method for discounting coupons and the redemption value. However, the exact functional form is determined by market or dealer conventions
The rate of return you receive if you hold a bond to maturity AND reinvest all of the interest payments at the YTM rate. It is calculated by taking into account the total amount of interest you will receive over time, your purchase price (the amount of capital you invested), the face amount (or amount you will be paid when the issuer redeems the bond), the time between interest payments, and the time remaining until the bond matures.