The definition of hertz

(related variations: Hz hertz)
Hertz means cycles per second, and makes no assumptions about what is cycling. So, for example, if a fluorescent light flickers once per jiffy, it has a 60 Hz flicker. More typical for computers would be a program that runs once per jiffy and thus has a 60 Hz frequency, or larger units of hertz like kHz, MHz, GHz, or THz.