AutoCAD Explained - cadvideotutorials.com
The UNDO and REDO commands can quickly return your drawing to a previous state. Using the undo command from the keyboard gives you many more options for undoing actions as demonstrated in this video.
Table of Contents:
00:00 Using UNDO and REDO from the Quick Action Tools
01:11 Using UNDO from the Command Line to set more UNDO Options