Definitions for "yield spread"
The differences in yields on different types of debt securities, a function...
The difference between the yield on one kind of income investment and the yield on a standard investment, usually US Treasury Bonds. The yield spread between a bond and the benchmark US Treasury would tend to indicate the degree of credit risk expected for the bond. Not surprisingly, yield spreads are much higher for junk bonds than for high-quality corporate bonds.
The relationship between bond yields and the particular features on various bonds such as quality, capability and taxes.