What's hotkey?

A keyboard shortcut (or accelerator key, shortcut key, hot key, key binding, keybinding, key combo, etc.) is a key or set of keys that performs a predefined function. These functions can often be done via some other, more indirect mechanism, such as using a menu, typing a longer command, and/or using a pointing device. By reducing such sequences to a few keystrokes, this can often save the user time, hence “shortcut”.

Source: http://en.wikipedia.org/wiki/Hot_key