Keyboard shortcuts make you a lean, mean productivity-machine by allowing you to keep your fingers stationed on the keyboard, as opposed to moving back and forth with the mouse.
Use Spotlight to search for things like apps, documents, images, and other files.
Highlight the URL search bar in your web browser.
Duplicate an item. It’s faster than copying and pasting.
Post a new status on Facebook.
Empty the trash. (Careful, there are no take-backs for this one).
Cycle through tabs in apps like Finder or a web browser.
Put your computer to sleep.
Learn information about a selected file in Finder, including file size, date of creation, and dimensions (if it’s a photo).
Hide the windows of the current app in use.
Define any highlighted word.
Select all, copy, cut, or paste content in a jiffy.
Undo and redo actions.
Find a keyword
Open a new window, open a new tab, or close a tab in applications like Finder or a web browser.
Quit the program in use.
Reopen the last tab you closed (up to 10 tabs).
Rename a file. (You have to select it first.)
Bold, italicize, or underline text.
Take a screenshot of the entire screen.
5 useful Mac shortcut
25 Basic Mac Keyboard Shortcuts