Undoes the most recent action on a graphic object and goes back one step in the editing process, (Ctrl - Z).

Repeat the command to reverse several actions or press the arrow next to the icon to get a drop-down list of your recent actions with the most recently performed action at the top. Here you can select multiple actions to undo at once.

 

Alternative 1:

1.Select Edit > Undo.

 

Alternative 2:

1.Press in the toolbar.