Clock frequency is the speed of the internet logic elements. In most cases it is the rated speed, such as 3MHz, Hz = hertz or what used to be cycles. Our home power is in hertz or cycle, usually 50 or 60. The M = mega or millions. Other choices are K = kilo or thousands and G - Giga or billions The number is how many of what is stated.
375KHz thousand cycles per second was the speed of the very first microprocessor.
3GHz Three billion cycles per second is the speed of a fast current microprocessor.
The faster the microprocessor clock generally the faster the speed of the calculations and the speed of the functions it is preforming.
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