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.
A Tab-Separated Values (TSV) file format represents data separated with tabs in plain text format. The file format, similar to CSV, is used for organization of data in a structured manner in order to import and export between different applications. The format is primarily used for data import/export and exchange in Spreadsheet applications and databases.
You can also convert ONE into many other file formats. Please see the complete list below.