responsive design

Everyone’s talking about responsive design, but what does it mean?
“Responsive design, on the other hand, is an approach that web designers and developers take to adapt the layout of a site to enable small and large screen devices to share the same code base and content without the need of separate website properties. Through responsive design you only need to develop one codebase for all of your users, no matter what device they use.”
http://www.metia.com/london/mark-mower/2012/03/everyone%E2%80%99s-talking-about-responsive-design,-but-what-does-it-mean/

What do you mean by responsive design?
https://boagworld.com/design/responsive-design/

responsive design
http://whatis.techtarget.com/definition/responsive-design

Responsive Website Design – What Does It Mean?
https://www.youtube.com/watch?v=FEX83OT-W48