I made this diagram so that I can keep my collection of Wacom styluses sorted. For whatever reason, the Wacom Grip Pen an the Wacom Art Pen were designed to be nearly visually identical from the distance that you'd typically look at one if you were using it in your hand. However, each stylus comes with its own features and driver rule-set, so confusing one for the other can lead to unpredictable results (for a good example, click here to see JSVB Post #246, way back when I was trying to calibrate one of these pens and I got the values all wrong).
So, completely frustrated with confusing one stylus for the other, I made the above diagram to refer as to which pen is which. The Grip Pen is the Wacom standard stylus, and has basic features such as tilt and pressure sensitivity, a rocker switch and a virtual eraser. The Art Pen is more sensitive, and it also uses rotation so that if I use asymmetrical tips like a chisel, a calligraphy nib, or a filbert brush, I will get rotation-enabled results.