Some of them may not even describe a file type. Before Windows started using them to associate files with an application, people used extensions for all sorts of things. But that was a long time ago.

FileTypesMan allows you to view, add, remove edit file extensions and types on Windows 11/10. You can always manually set or change File Associations & Extensions.

Windows associates the file extension with Google Chrome and returns you to the table that displays the list of file extensions. Repeat this process for every file that you want to associate with ...

Back in the pre-Mac OS X and macOS days, Apple’s System 9 and earlier relied on hidden metadata to associate files with apps. File extensions, those bits of text that follow a period at the end ...