Hotkey
From ISBoxer
A Hotkey is a combination of keys you press to activate something, such as a Mapped Key. ISBoxer supports a wide range of input device buttons for Hotkeys, including G-Keys and M-Keys on Logitech G series devices, X-Keys devices, and many more.
A Key Combination, in contrast to a Hotkey, is the term used for a combination of keys that will be passed to the game. A Key Combination never has to match the Hotkey used to send it, and also does not support the additional devices (games don't typically have the ability to interpret those buttons).