A prototype is draft representation built to test ideas for layout, behaviour and flow in a system. Prototypes are an indispensable tool for resolving a large number of potential issues in a concept or business before too many resources are deployed to put a design into production.
A prototype might exist to test a small part of an experience, or encompass the behaviour of an entire system. The scale and scope can vary greatly depending on the intended reason for its creation.
Prototypes have the ability to demonstrate an idea with greater clarity and higher levels of engagement than any specification document ever could. We use prototypes in our workflow on every project, at various stages of a designs development and in user testing ideas before developing or deploying.
A prototypes fidelity can vary greatly; it can be a sequence sketches, a series of wireframes, a design prototype, a part or fully built system. Prototypes can be made on paper or on screen. Generally speaking the closer the simulation appears to the intended end design, the more accurate the output from prototyping. Sometimes however getting a less accurate answer faster is better than getting a more accurate answer slower.
Prototypes can be created by any member of the design team – usually the one responsible for the medium in which the prototype is being created (eg: design prototype created by the UI designer).