Digital imaging technology has moved so fast and quickly that you can no longer keep the view that a camera produces an image. When I say image, I mean your usual JPG, BMP, TIFF, etc etc, or otherwise a collection of pixels, each with a different shade or color.
Photography is "painting with
light".
I may speak figuratively, but the most obvious way to 'paint with
light' is to take a capture of
light which is made by a digital camera and stored as a
RAW file.
RAW editing software is then used to 'paint' with the
light. You could paint a certain
exposure in specific parts of the
light, and or paint deeper contrast and colour. In short, look to your
RAW file not as the final image, but if you like a canvas upon which you paint the gorgeous creations of your art.