“Prototyping is a crucial part of the product development process, but traditionally, it has been a bottleneck.
Product designers and engineers would create makeshift proof-of-concept models with basic tools, but producing functional prototypes and production-quality parts often required the same processes as finished products. Traditional manufacturing processes like injection molding require costly tooling and setup, which makes low-volume, custom prototypes prohibitively expensive.
Rapid prototyping helps companies turn ideas into realistic proofs of concept, advances these concepts to high-fidelity prototypes that look and work like final products, and guides products through a series of validation stages toward mass production.
With rapid prototyping, designers and engineers can create prototypes directly from CAD data faster than ever before, and execute quick and frequent revisions of their designs based on real world testing and feedback.“
Formlabs has a great write up of the whole rapid prototyping process. They break it down to what it is (mainly 3d printing in focus), the cycle of design, build, test, repeat (iterate), and covering the differet types of prototypes. These prototypes are the proof-of-concept (early product validation) , the looks-like (where the visuals and user experience UX is refined), the works-like prototypes (refining the internals of how the product works), and the engineering prototypes (as close to the final design without cutting tooling or NRE for production parts). They cover many of the types of tools that are used during rapid product development with some basic descriptions and pros and cons to them.