One site for every screen. That’s responsive design.
“Day by day, the number of devices, platforms, and browsers that need to work with your site grows. Responsive web design represents a fundamental shift in how we’ll build websites for the decade to come.” – Jeffrey Veen
Visitors are going to see your sites from an increasing number of devices and browsers, including netbooks, tablets and mobile browsers.. This made the website developers to design a responsive website that can be accessed from any smartphone and any mobile device in the future. The main reason is simple. It is estimated that mobile web browsing will surpass desktop internet browsing by 2015.
For more information about responsive design and possibilities of WordPress responsive themes check out the following infographic made by Graphs.