This action set contains two Photoshop actions – one to save your file as a PSD, and another to save as a Jpeg.
It would be fair to ask “Why do you need actions for that? Just use File>Save As.”
Yes, of course that’s true. Simply hitting Ctrl-Shift-S (Cmd-Shift-S on a Mac) will bring up the Save As dialog. But there’s one limitation to that (the reason I was asked to make these actions) – the Save As function automatically gives you the same file format as you had before. If you have a PSD file, and you want to save it as a Jpeg, you have to go to Save As, then manually choose Jpeg from the file format pull-down menu.
These actions bypass that small piece of manual intervention.