Responsive Design is a web design approach where layouts adapt to different screen sizes, devices, orientations, and resolutions.
It matters because a website is often the first serious evaluation point for a buyer. Good design reduces confusion, builds trust quickly, supports accessibility, and helps visitors take the next step without feeling pushed.
Example
A three-column service grid can become two columns on a tablet and one column on a phone. Text and buttons remain within the screen, while the same service information stays available at every size.