For my Windows owning friends, they often ask where is the ‘Print Screen’ button on Macs, and many Mac users are not aware that there is a handy short cut for doing a screen grab, even if it involves a little bit of finger gymnastics. As you can see you hit the Shift-Cmd-3 buttons simultaneously:
And highlighted here:
This will drop you a full screen, screen grab onto your desktop, brilliant!
And even better, you can use a similar short cut to do a selection of the screen! Using Shift-Cmd-4:
This always gives delight when I show someone for the first time, and makes you look like a pro!