Hotkeys

In computing, a keyboard shortcut is a series of one or several keys that invoke a software or operating system operation (in other words, cause an event) when triggered by the user. The meaning of term "keyboard shortcut" can vary depending on software manufacturer. For instance, Microsoft differentiates keyboard shortcuts from hotkeys ("mnemonics" on Windows) whereby the former consists of a specific key combination used to trigger an action, and the latter represents a designated letter in a menu command or toolbar button that when pressed together with the Alt key, activates such command—whereas a "hotkey" on Windows is a system wide shortcut that is always available in all contexts as long as the program responsible for it is running and not suspended.

Keyboard shortcuts are typically a means for invoking one or more commands using the keyboard that would otherwise be accessible only through a menu, a pointing device, different levels of a user interface, or via a command-line interface. Keyboard shortcuts are generally used to expedite common operations by reducing input sequences to a few keystrokes, hence the term "shortcut".

To differentiate from general keyboard input, most keyboard shortcuts require the user to press and hold several keys simultaneously or a sequence of keys one after the other. Unmodified key presses are sometimes accepted when the keyboard is not used for general input - such as with graphics packages e.g. Adobe Photoshop or IBM Lotus Freelance Graphics. Other keyboard shortcuts use function keys that are dedicated for use in shortcuts and may only require a single keypress. For simultaneous keyboard shortcuts, one usually first holds down the modifier key(s), then quickly presses and releases the regular (non-modifier) key, and finally releases the modifier key(s). This distinction is important, as trying to press all the keys simultaneously will frequently either miss some of the modifier keys, or cause unwanted auto-repeat. Sequential shortcuts usually involve pressing and releasing a dedicated prefix key, such as the Esc key, followed by one or more keystrokes.

...
Wikipedia