How to take a screenshot of a specific area of your desktop in Mac OS X

  1. Pull up the application, window, or other item you'd like to take a screenshot for. This works for images on the web or virtually anything you could think of.
  2. On your keyboard, press Command + Shift + 4 and then release all keys.
  3. You will now see that your mouse cursor has turned into crosshairs that you can move around.
  4. Drag the cursor to where you'd like to start one of the corners of the screenshot and press down and drag the mouse over the area you'd like to capture.
  5. When you're done selecting the area simply release your mouse button.
  6. Now check your desktop and you should see a new .png file that contains the screenshot you just took.