Prototypes

noun

1. An original form or object which is a basis for other forms or objects (particularly manufactured items), or for its generalizations and models.
2. An early sample or model built to test a concept or process.

   "The prototype had loose wires and rough edges, but it worked."

3. A declaration of a function that specifies the name, return type, and parameters, but none of the body or actual code.
4. An instance of a category or a concept that combines its most representative attributes.

   "A robin is a prototype of a bird; a penguin is not."

5. A type of race car, a racing sports car not based on a production car. A 4-wheeled cockpit-seating car built especially for racing on sports car circuits, that does not use the silhouette related to a consumer road car.