1. Short for gigahertz, GHz is a unit of measurement for alternating current (AC) or electromagnetic (EM) wave frequencies equal to 1,000,000,000 Hz.
2. When referring to a computer processor or CPU, GHz is a clock frequency, also known as a clock rate or clock speed, representing a cycle of time. An oscillator circuit supplies a small amount of electricity to a crystal each second that is measured in KHz, MHz, or GHz. "Hz" is an abbreviation of Hertz, and "K" represents Kilo (thousand), "M" represents Mega (million), and "G" represents Giga (thousand million).
In general, the higher the GHz number for a processor, the faster the processor can run and process data. The first 1 GHz processors for consumer computers were released in March of 2000 by AMD and Intel. Today, processors are reaching 3.8 GHz or higher speeds.