A prototype is an initial or early model of a product or information system. It is usually built for demonstration purposes or as part of the development process.
Prototypes are used to test the design, functionality and capabilities of a new product, usually before being manufactured and sold to the mass market. It is most commonly used in areas such as semantics, design, electronics and software programming.
There are many different kinds of prototypes from Proof-of-Principle Prototypes to User Experience Prototypes. Specific prototypes test and explore different aspects of intended design and functionality. For example, a Visual Prototype only tests the size and appearance of a product or device, not the functionality.