You can rename a file many different ways on a Mac. In the Finder, you can click the file name after a file is selected, press the Return key, or choose File, Rename. You can also rename files in the app that you are using to view or edit it. You can click on the name in the title bar or choose File, Rename. You can rename files in the Finder or an app and the other will understand the change and follow along without a problem.