Final answer:
A prototype is a working demonstration of selected portions or the entirety of a future system, used in the design process to test, identify issues, and refine the design before final production.
Step-by-step explanation:
A prototype is a working demonstration of selected portions of the future system. Prototypes serve multiple purposes during the design process, including testing design decisions, identifying potential problems, and evaluating whether a design meets specified constraints and performance criteria. While prototypes may be developed for different aspects of a design, such as just the electrical system in a larger mechanism, they help to refine the design before progressing to the final production.
In some cases, prototypes can be physical, crafted from materials similar to those envisioned for the final product or cheaper alternatives to save on costs. Alternatively, virtual prototypes can be generated using computer-aided design and drafting (CADD) software, which might simulate various design aspects, reveal flaws, or improve understanding without a need for a physical representation. The prototyping phase is critical in the test and evaluate cycle of the engineering design process, where a prototype is often iterated to resolve identified issues and refine the design.