Just saves the current player.ply file. Can be restored with the point below.
If you want to rollback one or more player from the tool just select this option.
Just send a request to your Saves folder to update that player.
All players are also in your tool Player directory. With that option you push that ID to your Saves folder on your server.
Basically just the local / offline version of the "Impersonate" feature. It grabs the ID of the player and overwrite it with your player ID in your given creative Saves folder (set in the Config)