Adaptive design
While Responsive design works to create a universal look and feel with one design that varies from device to device, an Adaptive design has a different approach. Adaptive design is designed to detect the user device and to redirect the user to a website designed especially for this resolution.
First introduced by Aaron Gustafson in 2011 in his book Adaptive Web Design: Crafting Rich Experience with Progressive Enhancement, an Adaptive design has the main difference of having a totally different website on specific resolutions. Resizing the browser has no impact on the design.
The best example of Adaptive design isAmazon.com, which displays an entirely new layout of the website on tablet and mobile:
Amazon Website in desktop, tablet and mobile.
If you try to resize your browser, you can see that the design doesn't change any lower than 999 px.
Note
A tool that you can use to test the Responsiveness or Adaptiveness of a website is the inspect tool of Google Chrome. You can just right...