To make rapid prototypes is a good way to test your ideas and even get user feedbacks without having to move into production at once, especially when you are not quite sure about the dimensions, the assembling to fit other parts, etc. In this way, you can save a lot of time, energy, and money by encoutering and solving problems well BEFORE your final product is developed and released. You know, tooling for production is almost the biggest investment for a new project. Usually, rapid prototypes are made out of ABS, by CNC Machining, 3D printer or SLA/SLS.

3D Printer Prototype	Photosensitive Resin SLA Prorotypes
SLS Prototypes Laser Rapid Prototyping	CNC Machining 3D Modelling