Definition of gigahertz unit: = 109 Hz. Billion Hertz. How many cycles happen in one billionth of a second. Cycle per 10 -9 sup> sec. Example: Computer processor cycles (clock rate) are measured in GHz.
Definition of revolutions per minute unit: = Hz/60. The number of cycles that occurred in one minute. Cycle may be periodically repeating event. Symbol is rpm (revolutions per minute), it is the sixtieth part of Hertz.