What is CAD?
Computer Aided Design is the process of using computer software to draw designs for products. CAD software has many applications, including designing buildings, vehicles, electronic circuit boards, and many other products. CAD software is used where hand-drawn technical drawings would have been traditionally used.
CAD software can often produce photo realistic renders of the designs to show how they might finally look (customers tend to like this).
AutoCAD and SolidWorks are two common examples of CAD software.
Note that although CAD software is used to create 3D models, it is not modelling or simulation software. CAD software is used to create drawings with accurate measurements so designs can be tested and then followed to create products. Modelling software is used to test outcomes based on mathematical representations of phenomenon (such as a car crash model or a climate model).
What is CAM?
Computer Aided Manufacture is an extension to the CAD process. CAM involves sending CAD designs to machines that can then create them automatically. Now, obviously a house or a car cannot be automatically created by a machine, but simpler components such as machine parts and circuit boards can be.
Even if a complex design cannot be built using CAM, the process can be used to build a prototype of the design. In this video, a CAD design is sent to a CAM machine which creates a model of a car by gradually etching away a block of material.