ahhhhhhhh now we are back in familiar water
I gurantee you the disk is not changed/ altered in any way during partitioning or formatting
both partitioning and formatting both are nothing more than a written code for the rules of disk use ( a road map so to speak)
they are nothing more than directions to the system of where to start & stop writing on the disk platters according to cylinders and disks.
you could google research "hard drive geometery" if you want a Tylenol moment
many times a user with a botched or crashed OS will reformat the drive only to find install problems or stability issues. These are the result of the previous install left data bits not wiped during the formatting process'
when this occurs a simple zero fill utility is used (like boot n nuke) to write zeros during several passes to each sector of the hard drive, now this is SLOWWWWWWWW it takes about one hour to zero fill 20gigs of drive space!
the zero fill also removes all previous partitions and formatting info/ file system blah blah and gives you the same fresh start you have with a brand new drive out of the box.
enjoy