High- fidelity prototyping
-visualize requirement in detail
-Discover usability issue, especially with interactive behavior
-Develop a UI specification
-High-Fidelity prototypes reach from more detailed paper prototypes to fully interactive simulations
-From the level of detail of HTML prototypes on, users can see dialog windows,react on messages and enter from data
show the real system behaviour in an interactive manner rather than just presenting static screens.