HTML and CSS Certification Practice Test

Media queries play a crucial role in responsive design by defining breakpoints where different styles should be applied based on the characteristics of the device displaying the content, particularly the screen size. When a media query is activated by specific conditions, such as the width of the viewport, it allows developers to determine which CSS rules will be applied to ensure that the layout and design of a website remain flexible and visually appealing across a range of devices, from smartphones to desktops.

By using media queries, developers can optimize the user experience by adjusting font sizes, repositioning elements, and even hiding or displaying certain parts of the layout depending on the screen resolution or orientation. This capability is fundamental to creating responsive web designs that adapt seamlessly to various display environments. The statement accurately captures the primary use of media queries in this context.