In web design, a modal acts like a child window or dialog box that appears on top of the main webpage content. It creates a visual overlay, often slightly dimming the background to further emphasize the modal’s content. A key characteristic of a modal is that it requires direct user interaction to be closed. This means the user must perform an action like clicking a close button (usually an “X”), clicking outside the modal’s boundaries, or pressing the ‘Escape’ key (if enabled).