A user interface design blueprint for a website (UI). Wireframes are simplified illustrations of how information and functionality interact in a layout, sometimes sketched by hand. They concentrate on the arrangement and placement of components on a page, but they rarely go into detail regarding the final visual design. Photographs, for example, are represented by a box with an X through it. Because the same elements must be reordered for multiple screen sizes, wireframes are a crucial step in responsive web design.