CAD originally meant Computer Aided Drafting because in the early days CAD was really a replacement for the traditional drafting board. Now, CAD usually means Computer Aided Design to reflect the fact that modern CAD tools do much more than just drafting.

CAD is sometimes translated as "computer-assisted", "computer-aided drafting", or a similar phrase. Related acronyms are CADD, which stands for "computer-aided design and drafting", CAID for Computer-aided Industrial Design and CAAD, for "computer-aided architectural design". All these terms are essentially synonymous, but there are a few subtle differences in meaning and application. CAM (Computer-aided manufacturing) is also often used in a similar way, or as a combination (CAD/CAM).