A prototype is a basic working sample of the final product on which the other forms are developed.
Following are types of prototypes classified on the basis of what they represent:
1. Functional prototypes: These prototypes are designed to imitate the functions of the final product as close as possible. The look of prototype is not a matter of concern here.
2. Display prototypes: These are designed with a focus on the look and feel of the product. In appearance they should be as close to the final product as possible.
3. Miniatures: Miniatures focus on both the functional and appearance of the product.

Listed below is the classification of prototypes on the basis of how they are use:
1. Throwaway prototype: These are models which are eventually discarded and not used in the final product.
2. Evolutionary prototype: Here the prototype is developed such that it can be further used in the final product.

You can read more about prototypes in this article: https://www.feedough.com/what-is-a-prototype/