Yield is the actual return on the investments. There are different types of yield
Coupon yield: Coupon yield is the fixed interest rate on a government security or bond e.g. 12.00% GOI 2008 where 12.00% is the coupon yield. This yield does not reflect the change in the interest rate, inflation rate or any other economic factor.
Current yield: Current yield is the return on the government security or bond depending on its purchase price.
e.g. An investor 'A' purchases 12.00% GOI 2008 at Rs 100 and an other investor 'B' purchases the same instrument at Rs 110.
The current yield of investor 'A' will be =12.00%
The current yield of investor 'B' will be =10.91%
Yield to Maturity (YTM): Yield to maturity is the discount rate that equates present value of all the cash inflows to the cost price of the government security or bond. This is actually the Internal Rate of Return (IRR) of the government security or bond.