The difference between graphics like clip art and pictures, and Drawing objects like AutoShapes and WordArt, mainly lies in what you can do to them after you've inserted them into your document.
Clip art and pictures are imported from outside of Word, so you do not have too much control in modifying them. You can adjust the colors and brightness, and crop out parts you don't want, but you can't change the actual colors. For example, if you import the clip art of a green turtle, you cannot make it a red turtle.
You create AutoShapes and WordArt yourself, so you have more control over their modification. You can rotate or flip them, change their colors, adjust the shapes, group them together, etc.
So, the basic concept is that the more control you had in creating an image, the more control you have in modifying it.
Copyright 1997 by the Curators of the University of Missouri