My passport essential questions - re deleting files, etc

what does “damaging the partition” mean?

how is that different than damaging files?

And…

If I by deleting a few folders on the passport, and then manually dragging them back over to the passport from the hard drive, in my computer…

will that have damaged my backup?  Cuz, that’s what I did. Will it only be those folders that are damaged? How are they damaged?

If I ever want to delete some files or folders from my passport how do i do it  without erasing all the files?