The file that stores macro-enabled slide shows and presentations. PPSM stores a set of slides with graphics, audio and video information, which cannot be edited. It’s used solely to view the generated presentations. To run PPSX file macros, you should first save the file with the PPSM extension.
The extension allows you to save audiovisual and textual information as a presentation or a slide show. Is used solely for viewing the created presentation and has no editing capabilities. It’s based on the XML format and can be opened with PowerPoint 2007 and newer versions. The file may be viewed by the users who do not own a commercial PC version of MS PowerPoint but who could still view the presentation using PowerPoint Viewer.