Computer Aided Design and Drafting
CADD or CAD stands for Computer Aided Design and Drafting. This is different from both "draw" and "paint" programs in which measurement is central to its capabilities. While a "paint" program lets you manipulate all pixels in an array of pixels which make up an image, and a "draw" program goes a step additionally: it is composed of separate objects or entities, as circles, lines and so on. It may give facilities to group these in any object.