Apple/MAC Computer Shortcuts
The Basics
Cmd+Z: Undo
Perhaps the most useful keyboard shortcut ever invented, Cmd+Z (like Ctrl+Z on a Windows machine) undoes your very last action. This works across multiple programs, whether you've accidentally deleted a file, applied an image filter you don't like, or erased pages of carefully crafted prose.
Cmd+W: Close
Cmd+Q: Quit apps
When you click the red "x" in the top-left corner of an application window, macOS won't actually shut down the program completely, though it will close the selected window. If you're accustomed to Windows machines, you may have to adjust to this quirk—and to the fact that, because it leaves programs running, it can slow down your processor speed. To properly shut down an application, choose Quit from its menu—or better yet, employ this keyboard shortcut.
No matter what you're doing on the computer, you can start a search from just about anywhere by hitting Cmd+F. In your browser, you can search the current webpage; in Finder, you search the contents of your hard drive; in iTunes, you search your music library or the store; and so on.
Return: Rename
If you spend a lot of time renaming files, this shortcut will really come in handy. Once you've selected the file in Finder, you hit the Return key, type out the new name, and hit Return again when you've finished. Then move on to the next file by moving the cursor.Better macOS Navigation
Cmd+number: Change the Finder view
Finder offers several different ways to view your files. You can switch between these options by pressing CMD and then a number. Cmd+1 lets you view each file as an icon, Cmd+2 as a list, Cmd+3 shows the contents of a set of folders as a series of columns, and Cmd+4 gives you the cover flow perspective. Whichever view you end up using, the arrow keys will let you navigate through lists, columns, and files—all without having to reach for the mouse.
Need to cut down on on-screen clutter? Simple but effective, Cmd+H hides all the open windows of the application you currently are using, and switches the foremost application to the most recent one. Keep on hiding each application, and you'll wind up with a clear view of the desktop. Try adding the Option key for the opposite effect: Cmd+Opt+H hides all the open windows of all the open applications, except the one you're using right now.
Cmd+Tab: Switch apps
A quick tap on the Cmd+Tab keyboard shortcut will switch you from your currently-foremost app to the app you were using immediately before; another tap will take you back again. Hold down the Cmd key even after you press Tab, and you'll see icons for all your open apps: Hit Tab to cycle through them.
Space: Quick Look
The Quick Look shortcut is perfect for looking at a series of images or other files without fully opening them in an application. Just select the file you want to preview in Finder and hit Space. To close this view, tap Space one more time. You can also select a list of several files and press Cmd+Opt+Y to access a Quick Look slideshow.
Cmd+Opt+D: Show or hide the dock
As useful as a Mac's dock of app shortcuts is, it can eat up some valuable screen space. On the occasions when you want to quickly hide it from view, just hit Cmd+Opt+D. Press the shortcut again to reveal the dock once more. If you find that you prefer the dock-free look, go to System Preferences, where the Dock entry lets you automatically hide it when it's not in use.