Faq/General/140/en

What this option is for?
First of all, to avoid any confusion, a clarification on the "neighboring" option: 

The information is "reserved" to LibreOffice, making it possible, after a crash, to attempt automatic document recovery. The files generated by this regular backup (for which you can set the time) are not designed to be retrievable by the user.

The "user's" backups are those obtained by: .

That said, let us make no mistake about this "always" ... The built-in help (accessible via F1) indicates:

Saves the previous version of the document as a backup every time you save the document. Whenever LibreOffice creates a backup copy, the copy replaces the previous backup.The backup file has a .BAK extension.

The backup copy is done in the folder indicated in  (it is possible that the folder is hidden by default at the system level)

Examples :
 * No backup copy created
 * No backup copy created
 * No backup copy created
 * Creation of a backup copy in the state before the last save (same name + .bak)
 * No modification of the existing backup copy (because a new document doesn't generate a backup copy cf. cas 2)
 * overwrites the backup copy of the document with the same name, in the state of the current document before modification.

How to retrieve a document ?

 * It is almost mandatory to copy the file from the backup folder to another folder. This is for two reasons:
 * The .bak extension is not by default associated to LibreOffice. A double click on the file name will lead to a prompt asking you which program to use to open it. It is better to copy to another file to rename the document with its original extension (odt, ods...).
 * Opening and modifying the backup copy within the backup folder will display an error during saving because, in the case of a modified document, LibreOffice is trying to create a backup copy with the same name in the same folder...