Hi Dhairya
The private backup area contains course backups that have anonymised user information and are available to admin users
When you hover over the file in the course backup they are stored at http://sitename/pluginfile.php/999/backup/course/
The private files are stored on http://sitename /pluginfile.php/999/user/backup/ where 999 is a numeric folder
The course files are not directly accessible through the database you need to go through the backuup interface in Totara to download or restore.
It is possible to create an automated course backup and specify where to save to including an external drive
regards