What does "responsive design" refer to?

Responsive design refers to an approach in web development that ensures websites can adapt and provide an optimal user experience across a wide range of devices, including desktops, tablets, and smartphones. This involves using flexible layouts, images, and cascading style sheet (CSS) media queries to ensure that the content adjusts and looks good on whichever device it is viewed.

By focusing on responsive design, developers can create a single website that automatically adjusts its layout and features based on the screen size or resolution of the device being used. This is crucial in today’s digital landscape, where a significant portion of web traffic comes from mobile devices.

The other options focus on techniques or technologies that do not encompass the broader adaptive nature that responsive design promotes. Creating static web pages or limiting design to just HTML or CSS does not provide the functionality and adaptability that responsive design requires, which is pivotal for modern web development practices.