You can also press Command-O to open a selected file. As with double-clicking, the file opens with the app its file type is associated with. Select a file in a Finder window or on the Desktop, and press Command-down-arrow.
You can also open a file from the keyboard. If that app can open the file, the icon will highlight, and when you drop the file the app will launch (if it’s not already running) and display the file. You can open a file by dragging it onto an app icon, either in a Finder window, or in the Dock.
If you receive a file as an attachment to an email, you can open it by double-clicking it, as you would a file in the Finder. Only one app can open each file type when you double-click it, but as you’ll see below, you can open files with other apps, and you can change the default app that opens a given file type. By default, it opens with the application that is assigned to work with its file type so, if you have Microsoft Office on your Mac, a. The basic way to open a file on the Mac - and on Windows as well - is to double-click a file. Here are a dozen ways you can open files on a Mac. You can open files in windows, from menus, and from dialogs. But did you know that there are lots of different ways to open files? You can use your mouse, your trackpad, or even your keyboard. You open files every time you work on your Mac, most often, probably, by double-clicking them.