The Snipping Tool offers several different types of snipping options. To select an option, click the drop down arrow next to New on the Snipping Tool window. The Free Form option allows you to "draw" a freehand snip. When you select Free Form, the current window will appear slightly grayed-out and the cursor will turn into scissors. Hold down the left mouse button and drag the cursor around the object or area you want to copy. When you release the mouse, the image will appear in the Snipping Tool window.
Example of a Free Form Snip
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The second snipping option is Rectangular. When you click
Rectangular from the Snipping Tool, the window will be grayed-out and the cursor will become a plus sign. Drag the cursor across the area you want to snip, and a rectangular or square shaped image will appear in the Snipping Tool window.
Example of a Rectangular Snip

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The third snipping option is Window Snip. Click
Window Snip and the current window will take on a colored border. Click anywhere in the window, and the entire window will appear in the Snipping Tool Screen.
Full Screen Snip is very similar to Window Snip, except the entire screen will be snipped.
Window Snip

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Full Screen Snip

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The last used snipping option will remain selected unless and until you change it.