Cut, copy, and paste Apple mapped the functionalities to key combinations consisting of the Command key (a special modifier key) held down while typing the letters X (for cut), C (for copy), and V (for paste), choosing a handful of keyboard shortcuts to control basic editing operations. The keys involved all cluster together at the left end of the bottom row of the standard QWERTY keyboard, and each key is combined with a special modifier key to perform the desired operation: The IBM Common User Access (CUA) standard also uses combinations of the Insert, Del, Shift and Control keys. Early versions of Windows used
QWERTY studies administered by Dvorak himself before and after World War II. Economists Stan Liebowitz and Stephen Margolis have noted that rigorous studies are inconclusive as to whether they actually offer any real benefits, and some studies on keyboard layout have suggested that, for a skilled typist, layout is largely irrelevant – even randomized and alphabetical keyboards allow for similar typing speeds to QWERTY and Dvorak keyboards, and that switching costs always outweigh the benefits of further training on whichever keyboard you already use. The most widely used such alternative is the Dvorak Simplified Keyboard; another alternative is Colemak, which is