When I do a full backup using the Photoshop Elements backup feature, does it back up every file, as well as all photoshop tags, version sets, etc? Or does it just back up the tags and such but not the pictures themselves?

Here you go ... this is from an article discussing the backup features of Photoshop Elements, and I quote;

"Elements can create a full backup containing everything in your catalog (photos, video and audio clips, creations, tags, notes, and the catalog file itself), or it can create archive disks that contain only selected items that you want to give to friends or family. Also, to save time, Elements can do incremental backups where it only backs up the items that have been added or changed since your last backup. You can back up your catalog to various types of media."

Not sure which options you checked, or enabled for the backup, I would assume by 'full' that you got the whole kit and kaboodle ... maybe, even the kitchen sink. (<--- Kidding here, of course. :oP)

There was some additional information regarding backing up to removable media, as opposed to your hard drive. Just another consideration, in case of hard drive failure or other pc related problems.

And as purely an f.y.i ... you might want to post a thread like the one you created here ... on these particular forums instead.

No big deal though, a mod will probably move it to that location for you. :o)