What makes a website design responsive?
A responsive website is one that dynamically changes its appearance and behaviour based on the capabilites of the device that it is rendering to.
1. It does this from single code base.
2. It adapts in real time, such that a page refresh is not ncessary. You can resize a responsive website from wide to narrow and watch it change.
3. It uses the features of CSS to change the current style, by 'responding' to the capabilities of the device. Large screen vs. small screen. Mouse vs. finger. Landscape vs. Portrait. etc.
There are many websites that look good on the desktop and mobile, but if this duality is achieved with a full featured desktop site, and a scaled down mobile site then the site is not Responsive. It is partitioned.