As a result, a general obligation of designers and web developers became the need to provide high quality user experience for desktop, tablet and mobile devices.
Responsive design proved to be the best option to deal with the new needs.
Until a few years ago, websites were developed to fit most desktop screens, as the majority of Internet users were surfing the webthrough such devices.The most widely used monitors were 800 or 1024 pixels wide and as a result, website designs should have been of that size. Gradually, market was flooded with devices with different screen sizes and designers started to want their websites to display equally on all of them.
Responsive design turned out to be the solution to these problems. In the beginning of the 21st century terms such as fluid design and liquid layout were something like primitive versions of responsive design.
If companies want to be successful, they have to comply with the large number of mobile Internet users. Websites must be optimized for all device sizes.
Responsive websites use one Internet address and one programming code. This is very helpful for two main reasons:
1. You no longer need to create several designs for you website.
2. You no longer need to maintain several different domains.
Regardless of the device, users will see one and the same website. The website, on the other hand, automatically reorganizes and fits the screen. Responsive design ensures equal user experience in all possible website uses.
Resource: http://engage.synecoretech.com/marketing-technology-for-growth/bid/204297/A-Brief-History-of-Responsive-Web-Design .