In computing, a Control key Ctrl is a modifier key which, when pressed
in conjunction with another key, performs a special operation (for example,
Ctrl+C). Similarly to the Shift key, the Control key rarely performs any
function when pressed by itself. The Control key is located on or near the
bottom left side of most keyboards (in accordance with the international
standard ISO/IEC 9995-2), with many featuring an additional one at the bottom
right.
On keyboards that use English abbreviations for key labeling, it is usually
labeled Ctrl (Control or Ctl are sometimes used, but it is uncommon).
Abbreviations in the language of the keyboard layout also are in use, e.g.