If no one here understands what a sector-to-sector copy is, which is the
only true and identical partition copy process, I can't help that.

I guess this is a bit incomplete. Let me expand on this. Why would
anyone care or want it? For two reasons:

1). It completely and accurately preserves the integrity of the source
partition, and is an EXACT copy. And that can be useful for debugging
purposes. (If you've ever "been there", you know what I mean, but that is
another topic)

2). Because the partition copy operation is done disk sector-by-sector at
the disk partition level, and NOT at just the files level, ALL the original
folder AND subfolder date/time stamps are preserved in the destination
drive's partition. That is part and parcel of maintaining an accurate and
complete generational copy.

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Incidentally, I just found a copy of the Casper Guide (pdf file) and looked
at it, and, as expected, it doesn't really explain this well. It's a
superficial explanation, at best, which is probably ok for the average Joe,
since all he generally just wants to make a clone of his source disk should
that disk fail, end of story.

But the option in Casper that is more related to what I'm talking about
would have to be the "Copy a Drive" option, which isn't even really
explained in the manual (it's just mentioned).