How does Elements Organizer save files?

Using Photo Editor, I have used File:Open, made a few image enhancements, and am ready to save the file. If I don't expect to make further changes, I use Save As and add a character to the filename to identify it from the original, and leave the folder and file type unchanged. I have left the 'Include in Elements Organizer' checked. Does that create the new file with a different name in the same folder where the original was opened PLUS an Organizer file? (Or just the edited file?) On the same note, when I Import files into the Organizer, does that actually create a new file, or just a reference link that Organizer uses it if I choose to re-open it from the Organizer, rather than from the Pictures folder? If I know I want to come back to the file for further editing, I should save the file as a PSD type - correct? That goes back to the folder from where it was opened (if I didn't change the location) - correct? If all the preceding presumptions are correct and I don't import anything new to the Organizer, are the only files in the organizer the ones I have edited (which would be a mix of JPGs and PSDs, depending on how I saved them)?