.PPS File Extension
File TypePowerPoint Slide Show
This file is saved in a binary format, which requires a specific program to read its contents.
Slide show created with Microsoft PowerPoint, a common program for creating presentations; saved as a completed slide show, which can be viewed by either PowerPoint or PowerPoint Viewer; not editable like a .PPT file.
NOTE: Beginning with PowerPoint 2007, PowerPoint slide shows are saved in the OpenXML format with a .PPSX extension.