What is computer design?

Shortly and essentially, Computer Graphic Design is all visual arts and designs made with computers. Well, first of all Design has a lot of branches. Computer Graphic Design might be considered 3D modeling, graphic design applied to digital application, but the latter would be more like Digital Design. If you take the answer literally, so you have graphic design made purely by computers or to be applied on computer interfaces, no matter if it is 3D modeling, 3D animation, 2D drawing and animation, layout, visual effects, video editing, and the like.