File represented by .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 XLSM extension is a type of Spreasheet files that support Macros. From application point of view, a Macro is set of instructions that are used for automating processes. A macro is used to record the steps that are performed repeatedly and facilitates performing the actions by running the macro again. Macros are programmed with Microsoft's Visual Basic for Applications (VBA) from within the Excel Workbook using the Visual Basic Editor and can be run/debug directly from there.
You can also convert ONE into many other file formats. Please see the complete list below.