Answer: A Boss Button
A Boss button is a simple keyboard shortcut, often a single button like F10 or Scroll Lock, which is included in some applications or exists as a separate helper application that lets the user work fast can hide or end a program that is not appropriate.
While many modern applications ̵
Since then, the Boss key has evolved, and now you can also configure computers to switch to a legitimate application, minimize and lock the affected application, switch to an alternate desktop, and perform other more demanding tasks. It is even possible to buy a peripheral foot pedal so that the triggering of the boss button can be hidden under the desk without the keyboard being triggered to trigger the sequence.
Courtesy of the Department of Defense /Wikimedia.