I often need to step away from my Mac, and want it to go into Sleep mode. With a MacBook or MacBook Pro, I can simply close the lid and step away. However, when I want to put my iMac to Sleep, I need to mouse up to the the blue Apple in the upper left corner of the screen, then select “Sleep.”
However, as with most Apple functions, there’s also a keyboard shortcut to put your Mac into Sleep mode. Simply hold down the Command-Option-Eject buttons all at the same time for about two seconds. The Mac will instantly power down into deep Sleep mode.
If you’ve set up your Mac to require a password to wake from Sleep (which is a good security measure, especially for laptops), then this keyboard short cut also effectively serves to lock your Mac, until you wake it up and enter your password.