In the case of computers, the MHz or GHz speed is what the cores inside a processor chip run at, otherwise referred to as the ...

Processors work according to a clock that beats a set number of times per second, usually measured in gigahertz. For instance, a 3.1-GHz processor has a clock that beats 3.1 billion times per second.

In the case of computers, the MHz or GHz speed is what the cores inside a processor chip run at, otherwise referred to as the clock speed. There was a time when the whole computer ran at a set speed.