Responsive web design is a term used to describe a technology employed in web design. It allows a website page to be automatically displayed with a different style depending on the device used to view it. The website/device can recognise the type of device being used, decides if it is a PC, Tablet or small screen device (such as a smart phone) and then display the page in a style that will be most easily read on that device.
The rapid growth in the use of tablets and smart phones has in turn led to an explosive growth in the number of people using these devices to access the internet and view web content. When viewing a traditional web site design on a small screen the display is scaled down to fit the screen. That can make it difficult if not impossible to read… you may have to explode the display and/or move it around the screen to view the content you want.
Big advantage also for the web designer
In the past a web site often had two versions, one for standard or large screen display devices (PC’s) and another for small screen mobile devices. That meant the web designer had to create/maintain two sites. Using the new Responsive design technology revolutionised this as only one web site was then required regardless of the device on which it would be viewed.
As an example, this website uses a responsive design. If viewing it on a PC try re-sizing the display window and note how it adjusts the way the content is displayed dependent on the size of the window.
For those technically minded a flexible grid-based layout with HTML5 and CSS5 are used to achieve a responsive web page layout. There are an increasing number of Responsive design website templates available that will give you a head start if you want to create your own website.