Screenshots or Capturing what is on your screen:
Keyboard Shortcuts for taking pictures of the screen
Screen shots are saved as files on the desktop. If you want to put the screen shot in the Clipboard, rather
than create a file, hold down the Control key when you press the other keys. You can then paste the
picture into a document.
You can also take pictures of the screen using the Grab application (in the Utilities folder).
Some applications, such as DVD Player, may not let you take pictures of the screen.
Taking pictures of your screen with Grab
You can use the Grab application to take a picture of all or part of your computer screen. These pictures are often called "screen shots" or "screen captures."
1. Open Grab (located in /Applications/Utilities) and choose a command from the Capture menu.
2. Follow the instructions in the dialog for the command you chose.
To see information about a screen shot you've taken, such as the size and depth, choose Edit > Inspector.
To save a screen shot, choose File > Save. Grab saves screen shots as files in TIFF format. You can use the Preview application to view these files and export them to other formats, such as JPEG.