If you already have a website, you say surely it is enough to create a second website specifically dedicated to mobile. Moreover, many sites have already done. They have the main site for computers and a mobile site designed for mobile devices. But the downside of this plan is that it is an additional site to create and manage both sites. Moreover, it is clear that making a mobile dedicated website does not, because there are too many mobile devices with different sizes on the market. Rather than falter manage multiple sites, web designers began to imagine a solution to manage all device formats at one go.
The Responsive Design is a web design approach aimed at the development of websites offering a reading experience and best navigation for the user regardless of the end device (mobile phones, tablets, desktop computer...).

But what does it actually do?

This is a web site production technique, which allows for sites that automatically adapt to the available space on the screen. Technically, responsive web design is based on media queries. This is a feature offered by CSS, which allows to format websites. But first, imagine your responsive website. Responsive design is a new technique, which is just beginning to be controlled and demand to fit your organization. Prior to conceive a design, it was enough to make a model and it was over. Today, you must design an infinite number of designs to create a responsive design site. You must imagine how the page elements are organized in all resolutions, from the smallest to the largest. Fine, but you, you already have a website and now you are wondering how to make your "old" site, responsive design site.

Should you redo a new website in responsive design?

Technically, the responsive may be considered after the initial site design. But it's more complicated. An advice ? In this case, better to contact a web development agency. Here you will find the best php development company, to add a responsive design in your websites !