Uhh... ok.
I don't understand...
images saved in JPG or JPEG format are compressed in such a way that over time, their quality will degrade.
it's the same kind of thing that happens to YouTube videos that are uploaded, ripped, re-uploaded, re-ripped, and so on. their quality - both video and audio - begins to degrade and will eventually become so distorted that it'll be impossible to see the original picture or hear the original audio.