Question

short cut key for undo command is

Answer 1

Ctrl Z
 Press Ctrl key and after that press the Z key
That will Undo your command.
Or else, you can also press the undo button. is it's available in that software, or whatever you're working on.
Hope it helps!!!!

Answer 2

Heya friend,

THE ANSWER IS 

Short cut key for undo command is
Ctrl + Z

You can also do that by right clicking on mouse selecting UNDO.

Mostly this command is needed when we delete something by mistake while typing !!

There is another command redo which can be used after UNDO 
REDO =Ctrl +Y;



HOpe it helps!!!