Infographic: Responsive Web Design
Responsive web design allows a website to properly conform to the screen resolution of the device you are using to access the webpage. This is huge, because there are so many different ways that people use to access the internet now. As this infographic shows, 39% of time spent online is via mobile. Think about all the different types of phones with different screen sizes. then think about how irritating it is if you view a website and you're wasting time pinching the screen, minimizing, maximizing, trying to use search bars or forms that don't work...there's just no time for that!
The following infographic details a little history of responsive web design and has responsive web design best practices for web designers and web developers.