Hot Corners

> An alternative to using keys to invoke features is Hot Corners. You can set each screen corner to trigger an action when the pointer reaches it – say, to open Mission Control, move windows aside to access the desktop, or put the display to sleep. In System Preferences’ Mission Control pane, click Hot Corners to start assigning actions. To avoid accidents, hold one or more of the Ctrl, Opt, Shift and Cmd keys when selecting an action here; you will then need to hold those keys as well to trigger the action.