Before we wrap up this chapter, let's take a look at one last important function ”Undo. Many Mac users know that Command-Z means Undo. To be able to undo with just a keystroke is a wonderful thing. It gives you the freedom to make mistakes, to experiment; and that is how you learn. (I often wish life came with an Undo key.) If the Shortcuts bar is displayed, you can also click the Step Backward button to undo the last action. To redo any change you've undone, click Step Forward or press Command-Y. To undo multiple changes, click Step Backward as many times as needed, or press Command-Z multiple times.