What type of prototype retains some characteristics of the target system but is otherwise simple?

A low fidelity prototype is a simplified representation of a product that focuses on essential aspects without delving into intricate details or aesthetics. This type of prototype often uses basic materials, such as paper or wireframes, to convey the layout, functionality, and flow of the user interface. It retains key characteristics of the target system, enabling stakeholders to visualize and evaluate design concepts and user interactions without the distractions of advanced visuals or fully developed features.

By keeping the design uncomplicated, low fidelity prototypes facilitate quick iterations and feedback. They are particularly useful in the early phases of design when the primary goal is to brainstorm and refine ideas rather than finalize design details. This allows designers and users to concentrate on functionality and usability, making it easier to highlight aspects that need improvement based on user input.

High fidelity prototypes, on the other hand, are more detailed and closely resemble the final product, while functional prototypes focus on specific features rather than the overall experience. Usability prototypes typically prioritize the testing of usability aspects but may not simplify the system to the extent that a low fidelity prototype does. Thus, the definition and purpose of low fidelity prototypes position them as the correct answer in this context.