Responsive Design

Responsive design is a way of building a website so it automatically rearranges itself to look good and work well on any screen, from a wide desktop monitor to a small phone. The same page reflows its columns, images and menus to suit the space available.

It is like water taking the shape of whatever glass you pour it into, filling each neatly. Responsive design matters because most people now browse on phones, and a site that forces them to pinch, zoom and scroll sideways loses them to one that simply fits their screen.