Keeping up on the terminology that the group you employ uses can be challenging. Working with an organization that utilizes CAD, BIM, and VDC will help you know the caliber of expertise you should expect.

• CAD, or Computer Assisted Design, is the oldest methodology of the three. CAD utilizes both 2D drawings and 3D models & has been standard since the 1990s and has benefited the industry enormously in terms of allowing more complex design work to be executed quickly and more efficiently.
  
• BIM (Building Information Modelling) should be understood as a process of collaboration that is facilitated by the latest digital technology. By providing a holistic approach to construction that unifies design, building and documentation across a project's lifespan, BIM has caused considerable positive disruption to the construction industry in recent years. The key difference between BIM and 3D CAD is that a BIM file is much more information-rich, and includes details of performance characteristics, specifications, and other non-physical data embedded in a shared 3D digital model of the project.
  
• VDC, or Virtual Design and Construction, is the most difficult of the three terms to define — there is no single agreed upon understanding of this phrase. VDC like BIM is a process and a way of working that involves the management of integrated multidisciplinary performance models. It is a way of coming up with an ideal strategy for a given project that incorporates the right people and the right technology. VDC emphasizes collaboration and integrated working, and BIM is frequently a valuable part of VDC. BIM and VDC should not be considered analogous. BIM is a much more specific process than VDC, but both are essentially methods of planning and managing a project collaboratively.