IT MEans the file can only be viewed on Power point.
powerpoint extended or in short ppt extended
This is quite simple .ppt is Microsoft 2003 or earlier word file while .pptx is 2007 and up.
.ppt is Microsoft 2003 or earlier word file while .pptx is 2007 and up.
.pptx
.pptx
It could be either PowerPoint 2007 or 2010.
The earlier extension in power point was PPT. The newer extension is PPTX in power point.
The DOCX file extension is a Microsoft Office Word document. The"X" at the end of these extensions all stand for the XML (Extensible Markup Language) format. The DOC file is similar but without the XML formatting. The PPTX and PPT are MS Power Point Presentation files. The XLSX and XLS extensions are MS Excel files. Even if you don't have Microsoft Office, you can download Open Office for free and view most, if not ALL, of these file types. I hope this has answered your question adequately. Best wishes!
In Microsoft Office 2007 and 2010, the extension is .pptx, whereas in earlier versions it was .ppt.
I believe the default is .pptx (The old default used to be .ppt)
.ppt for versions up to 2003 and .pptx from version 2007 onwards.
.pptx is for Pwerpoint 2007 and onwards, including Powerpoint 2013.