Even if there are questions in restore that are not related to backups, the tag excerpt is unambiguous:
Returning data from a backup to its original location or to its successor.
While the name of the tag is ambiguous, its intended use is not; the tag was created on 2012/6/15 and this description was applied the same day. I suggest merging the tags and changing restore to an alias.
(Ironically, backup-restoration has no tag wiki description at all. The name says it all though.)