In a nutshell, Responsive Web Design means designing and building your website that would properly render in almost all the devices irrespective of the device size, browser, screen size, and so on.
As we discussed earlier, the best approach is to design the site for the smallest screen size first, and then to move upward. There are few very basic steps to be followed in order to achieve responsiveness and a good user experience.
The below points are only to get underlying concepts clearer and make your elemental background ready. We will later on see in detail how Bootstrap can be used to build and generate a full functional responsive website.
Viewport is the visible area of a web page on the device ...