The megahertz (MHz) equals one million hertz, widely used for radio frequency bands, early CPU clock speeds, and wireless communication standards. FM radio broadcasts in the 88–108 MHz range, while early personal computers operated at just a few MHz. One megahertz equals 1,000,000 cycles per second.

The gigahertz (GHz) equals one billion hertz, the standard unit for modern CPU clock speeds, Wi-Fi frequencies, and 5G cellular bands. A typical laptop processor runs at 2–5 GHz, while Wi-Fi operates at 2.4 GHz or 5 GHz. One gigahertz equals 1,000 megahertz or one billion cycles per second.