Responsive Web Design is an approach where the design content responds to the user — their environment and behaviour according to their device, screen size and orientation. It should always provide the optimum experience no matter the device!
An illustration showing the same website layout on different platforms.
The illustration above shows an example of this. On smaller screen sizes, less content may be shown to de-clutter the view or even removed completely. The orientation of the device is also taken into account, holding the device landscape may allow more room for more content to be shown.
THIS IS NOT AN APP. IT CANNOT BE DOWNLOADED FROM GOOGLE PLAY OR APP STORE.
Native app design is an application which has been written in a specific language for a specific device. So essentially an app written for the iPhone would have to be developed in a different language if it wants to work on a an Android. Double the work!
Infographic showing Native app design.
This is a proper app however, and is available for download on Google Play and App store.