The difference between Movieclip and Graphic is Movieclip you get to edit the 3D position and View, the Vanishing point, and Accessibility, this allows different symbols of Movieclip to be moved differently. Graphic however, has looping, where it uses the choosing of different Frames to move the object no matter if it is edited, this allows changes across multiple frames since this is only one object. Movieclip needs you to click "test movie" to actually see it, while Graphic allows you to see it by just clicking the play button. In short, Movieclip and Graphic have their own differences that allows people to edit their own animation in different ways.