The common keyboard contains a number of secondary function buttons. These include the Escape key (usually abbreviated as ESC), the Alternate (ALT) key, and the Control (CTRL) key. Escape generally allows the user to cancel an operation or exit from a screen. ALT and CTRL modify other keys from the QWERTY keyboard, similar to the way the Shift key does, to perform alternate functions. Other keys, Print Screen, Scroll Lock, and Pause, allow additional functions to be applied from the keyboard. These keys are in addition to the row or columns of Function keys (F1, F2, etc.). Appropriate software allows the user to tailor these Function keys.
