Just a method of differentiating two different, rather vague categories of work. I am wholly indifferent to the terms. From about 15 to 17, I spent portions of my summers helping my grandfather roof houses, or clearing land for an aunt, and various other, similar jobs. From 18 until almost 28, I was definitely blue collar. I worked in factories, paper mills, a hospital waxing floors, and construction (fiber optics). Then I joined the Air Force as a linguist, which, for the most part was a white collar sort of position (actually the collar was light blue or camouflage). As far as the poll goes, I marked both.