A bond’s duration is a measure of the bond’s sensitivity to interest rate changes.Duration may also be thought of as a measurement of interest rate risk.  It's common for new bond investors to confuse the financial term “duration” with the length of time until a bond is repaid.
The Macaulay duration (named after Frederick Macaulay, an economist who developed the concept in 1938) is a measure of a bond's sensitivity to interest rate changes.Technically, duration is the weighed average number of years the investor must hold a bond until the present value of the bond’s cash flows equals the amount paid for the bond.