A responsive website is a website that responds to different browsers. Laptops, notebooks, widescreen computers, tablets, ipads, smartphones etc all have different sized browsers. If you want the best user experience for your website then you need to make sure its going to look good on any kind of browser. Responsive web design takes all browser capability into consideration.
Why is responsive web design important?
In the last few years internet browsing has increased on smartphones and tablets so if your website is not mobile friendly your visitor will leave your site straight away. Responsive web design will eliminate your mobile website issues and ensure your website is readable on all devices. Some companies have made mobile versions of their sites which is good sometimes but this still frustrates the visitor. What if your visitor reaches your mobile version on a desktop! Making our visitors unhappy will reflect on your Google analytics. If a user leaves your site as quickly as they entered it then your bounce rate will be zero. This will result in being penalised by Google and with them ruling most of the search engine world this could be detrimental to your business.
A couple of years ago when I was working with a client and a Yell Salesman dropped in one day and tried to sell her a mobile website design. His speech was very persuasive and worrying to her as he went into detail on how her site would loose visitors because Google now require all sites to have a mobile version. After he left I told her not to worry and it wasn’t necessary for her to pay for a 2nd website just for mobile phone viewers. I had made her website for her on WordPress and had made it responsive. The guy insisted she needed a mobile site but he was just selling an unrequired service and thankfully she listened to me and didn’t go ahead with it.
For a more details about responsive web design please consult the Google Developers site: https://developers.google.com/webmasters/mobile-sites/mobile-seo/responsive-design