Any physical model can be a prototype.rapid prototyping company, The difference is the degree to which it reflects the expected finished part.
Very simple models can be made from paper, plastic, play-doh, foam, balsa, or other common household materials. These are examples of very low-fidelity prototypes, but they do have the advantage of being easy and inexpensive to make.
These types of prototypes may not run well or for long periods of time, so they are primarily used to get a visual idea of the design and compare it to other parts at scale.
More high-fidelity prototypes use modern machine tools and materials, including various 3D printing techniques, vacuum casting, rapid tooling for injection molding, and CNC machining.
like:
What are the common methods of prototype proofing?
CNC technology - prototyping made easier