Just saw an exhibit about him at our local high school, New Rochelle HS. We can claim him as one of our own as he lived and had studios here for many years.
I remember reading that he did not object to being called an illustrator rather than a painter. I'm not sure about the "technical" aspects or differences, but I don't think he cared enough about his detractors to let them bother him.
60 Minutes did a show on 'art' a few years back. They had all these weirdo 'artists' showing what they considered 'art' and people who were considered 'artists'. One 'art' object was a toilet seat within a picture frame. Many others, including a painting by an elephant, were just as insane. Anyways, when Leslie Stall asked them if Norman Rockwell was accepted in their circle as an 'artist', all agreed that he was not, just merely an 'illustrator'.
An illustrator uses the medium to convey a point or idea. A painter changes the color of a wall, and often the carpet it joins.