I Found this article about the Graphic Artist and Graphic Design, and I think it is very interesting. Some times I wondering the same thing…
Graphic Artists
Graphic artists, like all artists, create works that are born from or meant to convey an emotion or feeling, or are meant to set a mood. Professional graphic artists simply use their creations in a commercial way. Graphic artists craft scenes and images using visual media such a photographs drawings, and computer-generated images. These are used on everything from tissue boxes to the walls of buildings. Their work is used to market products and ideas.
Graphic Designers
Graphic designers solve visual communication problems with images and text. The key goal of graphic designers is to convey a message that causes the viewer to take some kind of action. This could mean getting a website visitor to move his eyes down the page or causing a consumer to identify with a logo or symbol. Artistic appeal is secondary to function, and the layout is meant to lead the eye in a natural sequence.
From- http://work.chron.com/graphic-artist-vs-graphic-designer-18514.html