How to Take a Screenshot
    You may need to know how to take a screenshot for your site records or to show a preview of something. Read this simple tutorial to learn how!
Windows Users:
Keyboard Command: ALT + Print Screen (PrtScn)
    After you have pressed ALT + Print Screen, open up a Paint program (Windows comes with a free, simple version of Paint) and paste it in.
Mac Users:
Keyboard Commands:
Command + Shift + 3 makes a PICT file of the entire screen
Command + Shift + 4 to change the cursor to a cross and click and drag to copy an area of the screen to a PICT file.
Caps Lock + Shift + 4 is the same as above except the cursor is a circle.
Add Control to any of these to copy to clipboard.
Credit
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