Multi-session save files save changes and additions to Puppy when it is install on optical media. Not to be confused with the SaveFile Save Files used for live disk and frugal installs.

When saving to a multi-session disk, it uses save directories. It makes a new save directory each time a save is done to the multi-session disk.

What you end up with is a bunch of different save directories. It is part of how saving to a multi-session disc works for burning to and reading from. They do not use a single save file that gets updated.

SaveFile Save File - AKA 'Pup Save' stores updates, in a frugal installation.