MAC Commands

How to Print Screen to a file on the desktop in Mac OS X
The basic functionality of taking a screen capture of a window or desktop in Mac OS X takes an image and dumps it to a file on the Mac desktop :
 * Command+Shift+3: takes a screenshot of the full screen (or screens if multiple monitors), and save it as a file to the desktop
 * Command+Shift+4: brings up a selection box so you can specify an area to take a screenshot of, then save it as a file to the desktop
 * Command+Shift+4, then spacebar, then click a window: takes a screenshot of a window only and saves it as a file to the desktop

How to Print Screen to the Clipboard on a Mac
This functions a lot more like Print Screen in the Windows world. If you want to do the equivalent of Print Screen to the clipboard so that you can paste it into another app, these are the commands you’d want to use:
 * Command+Control+Shift+3: take a screenshot of the entire screen (screens if multiple monitors), and saves it to the clipboard for pasting elsewhere
 * Command+Control+Shift+4, then select an area: takes a screenshot of selection and saves it to the clipboard for pasting elsewhere
 * Command+Control+Shift+4, then space, then click a window: takes a screenshot of a window and saves it to the clipboard for pasting