Difference between analog and digital computer ??

The analogue computer works on a continuous signal. The digital computer works on a discrete signal. The output is a voltage signal, they are not exact values and are in graphical form.

the answer to your question would be something called hertz. the unit of measurement called a hertz, which is one cycle per second, is used to measure clock speed. within one cycle, your computer processes, refreshes, or updates itself to the changes that it is going through. in the case of computer clock speed, one hertz equals one tick per second. the clock speed of computers is usually measured in megahertz (mhz) or gigahertz (ghz)