In terms of hard drive speed, what does "RPM" mean?

In terms of hard drive speed, what does "RPM" mean?

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The RPMs are revolutions per minute. Basically, inside the hard drive there are disk platters, and they're rotating just like a record on a record player would. It's rotating really fast, and the faster it rotates the faster the information is transferred from the hard drive to the processor. That in turn increases the read time and the write time on the hard drive, so RPMs are important.