Catalog Structure Backup

Well, if you turn on the Automatic Backup on Exit option, as I understand it, the most recent automatic backup will be used if there is a problem opening the catalog.  As far as I know, the manual File>Backup>Catalog Structure only option creates the same backup as the Automatic Backup on Exit option.  The only difference is that you can choose the manual backup storage location, but there is no option to change the automatic backup location which is:  C:\ProgramData\Adobe\Elements Organizer\Catalogs\_AutoBackup_.

The purpose is to keep a backup of just the catalog database without the media that is logged within the database.  This database can be used if you have a catalog corruption and it can be opened from the File>Manage Catalogs dialog.  The backup is saved in a location you specify.  And when you want to open that backup catalog, simply Browse to it from the Manage Catalogs dialog. 

Since the media is not backed up, the process is very fast and provides a safety net for any catalog mangement work that you have performed.