Yield spreads, like bid and ask spreads, are calculated for different assets. Bonds are the most commonly associated asset with yield spreads, and they are calculated in this manner.
A yield spread is the difference in yields between two bonds of equal size and value. As a result, if one bond has a yield of 10% and another has a yield of 5%, the yield spread is only 5%.
This is also applicable to Forex. For example, a high yield spread would look like this. Assume the yield curve for EUR/USD is 20% and the yield curve for EUR/GBP is 5%. Because these are both major currency pairs, calculating the yield spread on them is possible. The yield spread in this case would be 15%, indicating that more people will start to transfer to the EUR/USD pair in search of higher payouts.

The spread of yields refers to the difference in interest rates between two debt securities, typically of similar maturity but different credit quality. For example, the Treasury yield spread compares government bond yields (like the 10-year Treasury) with corporate or municipal bond yields. A wider spread indicates higher perceived risk in lower-rated bonds, while a narrow spread suggests confidence in the market.

Yield spreads are crucial for assessing risk appetite, economic health, and credit conditions. The credit spread (between corporate and government bonds) reflects default risk, while the yield curve spread (short- vs. long-term rates) signals economic expectations. Traders and investors analyze spreads to identify opportunities in fixed-income markets.