...started, or when a floppy is inserted? Thanks?

It depends on what sound you are talking about. It is most likely the disk starting to spin. Think, when the computer is off the disk is not moving but as soon as you turn it on it has to get to thousands of RPM's very quickly, the same with a car, if you rev the engine it is louder until it settles at an RPM, and then it is quieter. This is all because the device need to do more work to start the revolution and less to keep it going.

The Hard Disk Is In Its Self A Disk That Spins To Read The Drive It Does This At Very Fast Speeds Which Causes The Noises The Same With The Floppy Drive Or Its Just The Fan Running 2 Cool It Off.

the sound that you hear in a hard drive is made by the arm the laser eye is mounted on moving back and forth very rapidly. i would imagine that the sound in a floppy drive in pretty much the same thing...