RESPONSIVE DESIGN - DESIGN FOR SMARTPHONE, TABLET & DESKTOP
Not everyone visiting your website will be using a traditional desktop or laptop computer.
In fact all evidence shows that these desktop/laptop users will soon be in the minority. More and more people are now accessing the web using touch-based mobile devices such as smartphones and tablets. Moreover, mobile usage research from Google shows the biggest recent increase in those using these mobile devices occurred in the UK.
Making your website work better for mobile visitors
It's important then, especially if your site's target audience fits closely to mobile user groups, that you have a website that is easy and enjoyable to use for your mobile visitors, as well as those on desktop computers.
Unfortunately, most websites designed for desktop don't work very well on mobile devices. This is particularly true for smaller devices such as smartphones (small screened, touch based, web enabled mobile phones).