A screenshot takes a photo of the information that you have displayed on your screen. It can also be referred to as a screen capture or screen dump. It is taken either by a program running on the system or the operating system itself. It’s possible to take screenshots on computers running Windows, Linux or Mac. Taking a screenshot may be necessary to show how to use a specific program, demonstrate a problem that exists or show display output to others for tutorials posted on your personal websites or to share with friends and acquaintances on social networking sites.
There are multiple methods you can take to capture a screenshot using the Macintosh operating system depending on how you want to take the screenshot or how much of the screen you need to get an image of. Capture a screenshot of your entire desktop by pressing command-shift-3. It automatically saves itself as a PNG file on your desktop. If you need to copy it directly to the clipboard to paste into an alternate program, you can press command-control-shift-3 instead.
Create a screenshot of a limited portion of your desktop by pressing command-shift-4. The cross-hair appears on your screen and allows you to click and drag until you select the entire area you want to capture on the screen. Once the mouse button is finally released, the screenshot saves on your desktop as a PNG file. If using Mac OS 10.3 or earlier it will save as a PDF instead. If you would rather copy the screenshot to the clipboard instead of saving it as a PNG, press command-shift-control-4.
If you want to limit the screenshot strictly to the application you have open you can press command-shift-4 and spacebar at the same time. Your cursor will change to a camera which you can move around the screen until you select the application. Click the mouse button and it will save a PNG screenshot directly to the desktop. Press command-shift-control-4 and spacebar all at the same time to copy the information to the clipboard to make it accessible for other programs.
Apple also includes their own grab utility in Mac OSX, which is located in the Utilities folder under applications. It’s especially ideal to use if you need to show a program menu or cursor directly in the screenshot. It has a selection or window option to allow you to capture only a specific part of the screen. It even has its own built in timer function to allow you to prepare the screen for the capture before it takes the photo.