Save a screenshot on a Mac by pressing Command, Shift and 3 simultaneously. This saves an image of the entire desktop screen as a PNG file.
Users can take screenshots of specific aspects of the computer screen, such as task bars, menus, windows or limited areas of the screen. To do this, press Command, Shift and 4 simultaneously with a menu open, or press the combination and either highlight a window or click and drag to highlight an area of the screen. Adjust the highlighted portion of the screen by holding Option, Space or Shift and dragging the mouse cursor. All screenshots saved on a Mac using the Command prompt save automatically and are available on the computer's desktop.