Responsive web design is the term used for a website that changes and adapts its appearance for optimal viewing on all sized screens such as smartphones, tablets as well as laptop and desktop computer screens. It is sometimes referred to as 'Adaptive Webdesign', 'RWD' or 'Fluid Webdesign'. Websites that are not made responsive do not adapt to different screens and as such can be hard to view and navigate on small devices.
With increasing frequency, new websites are being made using responsive design techniques to eliminate the need for a stand alone mobile website. Such a decision also enhances the user experience drastically therefore leading to more sales and customer interaction as potential clients are not being frustrated by small text and almost impossible navigation.
Responsive web design works by using a script to detect the screen size the website is being viewed from. It can detect each device whether that be a smartphone, tablet or laptop- then uses CSS to display the site in an appropriate format. Images can be reduced where needed to fit to smaller screens, text is enlarged and menus change to a drop down system rather than horizontal system.
The advantages of using this type of design over having a separate mobile version of your site are stark: when you update your site, it updates for all devices; it displays correctly on all screens- sometimes mobile sites will be displayed on tablets, making them smaller than is ideal.
Many companies offer both mobile web design and responsive Webdesigner. With responsive web design techniques improving all the time, there seems little reason left to have a stand alone mobile site unless you would like to market differently to mobile users than you would to desktop or laptop users. For example, a fast food business may want to target people on the move with instant special offers but show laptop users their menu and upcoming promotions. In most cases though, a website would cater for all users in the same fashion and therefore a responsive design is the way to go.
Responsive web-design is the future of websites and companies that currently build their sites without this feature face having to pay for another new website in 2 years when they realise the mistake they've made. It is recommended that companies research the power and price of adaptive designs before committing to any new web design projects.