The PPS file format, standing for PowerPoint Slide Show, is a legacy file format developed by Microsoft for its PowerPoint presentation software. Unlike the standard PPT or PPTX formats, which open in an editable workspace, a PPS file is designed to launch directly into a full-screen slide show presentation mode the moment it is opened. This makes it an ideal format for distributing presentations to audiences who need to view the content without the ability to modify the slides, layout, or animations. While it is functionally identical to a PPT file in terms of content structure, the file association in operating systems is configured to bypass the editing interface. It was widely used in the late 1990s and 2000s for sharing slideshows via email, though it has largely been superseded by the modern PPSX format, which is based on the Open XML standard and offers better compression and data recovery capabilities.