Definition of: GHz (GigaHertz)
GHz or GigaHertz means One Billion clock cycles per second. The unit is used to measure the maximum frequency of circuit switch, or “state change,” for electronics. Since data change or computations involve a state change, the frequency is an upper-limit to performance. One GigaHertz (GHz) is 1000 MegaHzerts (MHz).
To understand the performance implications of higher GigaHertz, read our MegaHertz page. Because Hertz is to measure frequencies, it is also used for radio-frequency, but that has nothing to do with computing performance.