Answer
Responsive design makes one page adapt to different viewport sizes and user settings. • HTML provides semantic structure and responsive image choices. • CSS media or container queries control layout changes. • The viewport meta element helps mobile browsers use the intended layout width.
💡 Simple Example
<meta name="viewport" content="width=device-width, initial-scale=1"><main><img src="/images/class-small.jpg" srcset="/images/class-small.jpg 480w, /images/class-large.jpg 1200w" sizes="100vw" alt="Students in a classroom"></main>
⚡ Quick Revision
Responsive design combines sound HTML, flexible CSS, and appropriately sized media.