Files with .ONE extension are created by Microsoft OneNote application. OneNote lets you gather information using the application as if you are using your draftpad for taking notes. OneNote files can contain different elements that can be placed at non-fixed locations on document pages. These elements may contain text, digitized handwriting, and objects copied from other applications including images, drawings and multimedia (audio/video) clips.
Files with .POTX extension represent Microsoft PowerPoint template presentations that are created with Microsoft PowerPoint 2007 and above. This format was created to replace the POT file format that is based on the binary file format and is supported with PowerPoint 97-2003. The files generated can be used to create presentations that have same layout and other settings required to be applied to new files. These settings can include styles, backgrounds, colour palette, fonts and defaults. Such files are generated in order to create ready-to-use template files for official use.
You can also convert ONE into many other file formats. Please see the complete list below.