The most vital activity that fixed-income securities undertake pertains to maturity management in the interest rate-risk process for both investors and portfolio managers. There are different types of measuring tools which assess how sensitive a price of a bond would be to the change in interest rates using duration. While the duration measures like Macaulay and modified duration are highly known, the KRD pushes on the entire space of effective duration to finer degrees of changes in the yield or in the price of a bond or portfolio if the yields change at selected maturities, which in this case are referred to as "key rates." Hence, it will be ideal to have a treatment of KRD, distinguishing it from ED.