The term 'Unit of Speed' can refer to three different measurements: Mach, KNOT, and Baud. Mach is a unit of speed that measures the ratio of the speed of an object to the speed of sound in the same medium. KNOT is a unit of speed that measures the speed of a vessel relative to the water it is traveling through. Baud is a unit of speed that measures the rate of data transmission over a communication channel.