GHz stands for Gigahertz. This stands for one billion cycles every second. This is known to be a unit of frequency that can be used for different purposes. This can be used for the radio. It can also be used for sound, and also for computer processors.
MHz, on the other hand, stands for one million hertz for every second. This will usually find the applications that it would need with the use of physical vibrations. GHz can also be used to study the electromagnetic spectrum.
Since there are a lot of semiconductor technologies that have come up over the past years, GHz has started to become more popular and widely used in various industries as compared to MHz.