Computer Aided Design (CAD) is a critical tool engineers use to transform their napkin sketch ideas into actual three dimensional models. Inventor is a powerful software package that allows engineers to design parts, create assemblies, animate assemblies and create real life renderings of their models. CAD is one of the main ways an engineer can communicate their ideas to other parts of a company like Sales, Marketing and Technical Support. Some say a picture is worth a thousand words; well, a 3D animated model is worth a million.