pfix=ram is telling the boot process to not use the save file or folder.
Boot with no save.
It will boot into pupmode 5 and run as it does the very first time it ever booted, before a save was made.
This is a way to boot, if you think the save is bad, and you can still get it running to a usable state.
Shutdown and you get asked to make a save.
Note:
RAM was used for the name of the option, because it boots with everything loaded into RAM.
When booted using a save file/folder.
It is not everything loaded into RAM. All the Puppy SFS files are in RAM.
The save file/folder is just layered into the file system, but is still at the location it is stored at. Not in RAM.