When you receive a PowerPoint file, either over a corporate network or as an email attachment, the file extension indicates whether it is a show file (intended for viewing only) or a working presentation file. The show file has the file extension .ppsx, while the working presentation file uses the file extension .pptx at the end of the file name. Changing this extension changes the file type.

A PowerPoint show is the actual presentation that you view as an audience member. A PowerPoint presentation file is a working file in the creation phase. They differ only in their extension and the PowerPoint format they open in.

PPTX is the extension for a PowerPoint presentation.

PPSX is the extension for a PowerPoint show. This format saves presentations as a slide show. It is the same as the PPTX file, but when you double-click it, it opens in slide show view instead of normal view.