Whenever you make a mistake in typing, editing or accidentally deleting or overwriting something, you can easily reverse it with words Undo feature. to invoke the undo commands press ( CTRL+Z), or click the undo button on the quick access toolbar.
The Undo feature keeps a list of recently taken actions, and you can undo any number of them. The Undo command runs in a sequence from the latest action to the oldest action, for example, u can Undo the last five actions, but you cannot pick-and-cheese among those five: you must undo the all four in order to undo the fifth one. To undo, press and repeat (CTRL+Z) or repeatedly cleck the UNdo button on the access toolbar.
After you have undone one or more actions, the redo button becomes available on the Quick Access toolbar. It reverses Undo operations and is useful when you accidentally undo a command which you do not want (CTRL+Y) is its keyboard shortcut.