The pack contains two actions:

--- one action for creating a line art from a photo or a graphic image.   The action turns any colored image into a black line drawing. The black lines are separated from the background so you can change the color of the white background and the color of the black lines.
--- one action for creating clean line art from a scanned image of a drawing or sketch.  Use the action to separate scanned lineart from the background onto its own layer, so you can color underneath.

I saw many people asking how to separate their lineart from the background, or how to clean a line art drawing. With this action you obtain clean black lines on a transparent background.