What happens to the original photo that is uploaded?

Hi,

I'd like to use gallery for more than just sharing my pictures but
to archive them as well. Are the original images that are uploaded
kept as well as the resized verisons or are they resized and the originals
dumped?

If they are dumped can I get gallery to just keep them in case I need
them later?

Sorry I couldn't find this answer in earlier posts even though I'm sure
it must have been asked before.

Thanks,

Nic