PPS, PowerPoint Slide Show, files are created using Microsoft PowerPoint for Slide Show purpose. PPS file reading and creation is supported by Microsoft PowerPoint 97-2003. The more latest version of this file format is PPSX which is based on Office OpenXML standards. PPS files can still be read by latest versions of Microsoft PowerPoint, but newly created files can only be saved in PPSX file format. When a PPS file is shared with another user and opened, it starts as Powerpoint show unlike PPT file which opens in editable mode.
PPS is a binary file format that adheres to the specifications detailed in MS-PPT file format document. It consists of a number of streams to represent the overall document structure and data. These include:
Current User Stream
PowerPoint Document Stream
Summary Information and Document Summary Information (Optional)
Complete details about the PPT file format can be found in the MS-PPT specifications document that equally apply to PPS as well.