The file stores slides with presentations and slide shows filled with graphics, audio, video, and textual information. The format is identical to the PPT file, except for the editing feature, and is a bit smaller. Can be opened only in preview mode and prevents other users from changing the structure and content of the presentation.
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.