Prototype

A prototype is an early, working mock-up of a product or feature, built to test an idea before committing to the full, finished version. It can be as rough as clickable screens that only look real, made to see how people respond and where they get stuck.

It is like a show home or a concept car: convincing enough to walk through and react to, without being the final build. Prototypes matter because they turn arguments about what might work into evidence from real reactions, catching problems while they are still cheap and easy to change.