Will reverse or "undo" the most recent action that resulted in a change to the document. For example, if you accidentally deleted a graph, you can select "Undo Delete" and your graph will reappear. Multiple levels of undo (up to 64) can be set in Preferences. That is, you can reverse your last 64 actions on the page. Note that the text of this item will change to describe the type of action that will be undone, e.g. "Undo Move" or "Undo Deletion".

The Undo command changes to "Can't Undo" on the menu if you cannot reverse your last action.
 
 

Shortcut:

    Windows: CTRL+Z
    Macintosh: Z