PPTX vs. PPSX
A PowerPoint show is the actual presentation that you view when you are a member of the audience. A PowerPoint presentation file is a working file in the creation stage. They differ only in their extension and the PowerPoint format they in which they open.
PPTX is the extension for a PowerPoint presentation.
PPSX is the extension for a PowerPoint show. This format saves presentations as a slideshow. It is the same as the PPTX file but when you double-click it, it opens in Slide Show view rather than Normal view.
Editing a PowerPoint Show File
Sometimes, you want to make a few changes to the finished product, but all you received from your colleague is the show file with the .ppsx extension. There are a couple of ways to make edits to a .ppsx file.
Open the File in PowerPoint
Open PowerPoint. Select File > Open and locate the show file with the . ppsx extension on your computer. Edit the presentation as usual in PowerPoint. Go to File. Select Save As. In the Save As Type box, choose PowerPoint Presentation (. *pptx) to save the file as a regular working presentation file.
Change the File Extension
In some cases, you can just change the extension before opening the file in PowerPoint.
Select File > Open and locate the show file with the . ppsx extension on your computer. Right-click the show file with the . ppsx extension and choose Open file location. Right-click on the file name and choose Rename. Change the file extension from . ppsx to . pptx. Double-click on the newly named file to open it in PowerPoint as a working presentation file.