OS X20 A practical shortcut key

Command + UP ARROW: Scroll to the top of the page immediately

Command + DOWN ARROW: Scroll to the bottom of the page immediately

Command + semicolon: Toggle between misspelled words in a document

Command + 1 (2,3): Toggle before opening a tab in the browser

Option + DELETE: Delete one word at a time (not one letter)

Command + H: Quickly hide all open windows for active applications

Command + Shift + T: Open recently closed tabs in the browser immediately

Command + F3: Clears all application window previews from view immediately

Option + Shift + volume + +: small increase or decrease system volume

Control + Command + D: View the definition of the currently selected word

Command + M: Immediately minimize the open window to the dock

Command + Option + M: Minimize the open windows of all active applications immediately

Command + Option + W: Immediately close all active windows for any open application

Command + Option + D: Hide/Show Dock

Shift + Option + Left/right arrow: Select one word in any direction

Command + Shift + Delete: Empty trash

Command + Shift + 3: Screenshot of entire screen area

Command + Shift + 4: Screenshot of specific area

Fn + F12: Fast entry Dashboard

To use the following two shortcuts, you need to turn on the system's magnification, specifically to enter the System Preferences > accessibility, and then check "use keyboard shortcuts to enlarge."

Command + Option + 8: Quickly zoom in on the screen

Command + Option + Plus/minus key: enlarge/shrink screen as needed