How to take a screen shot with MacOS X

When using Mac OS X you can take a screen shot using the Grab application. The Grab application is found in the Utilities folder within the Applications folder. Grab's icon is
Grab application icon

Alternatively you can also use the following keyboard short cuts to take screen shots.

Shift-Command-3 Capture the screen to a file
Shift-Control-Command-3 Capture the screen to the Clipboard
Shift-Command-4 Capture a selection to a file
Shift-Control-Command-4 Capture a selection to the Clipboard

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