A controller keyboard can be used to allow the user to assign parts of Ableton to the keyboards keys, knobs, sliders and trigger pads.
The reason why I needed to use this is so that could trigger off different scenes and clips live without the use of a mouse.
The beauty of setting up a controller keyboard is its simplicity. You take the USB cable, plug it into the back of the keyboard and connect it to you computers USB slot. Your computer then does the rest by recognizing the hardware and is ready to use.