Responsive web design works by using a script to detect the screen size from the website is being viewed from. Responsive web design can detect each device whether that is a smartphone, any digital device, tablet, computer and laptop then uses CSS to display the website in an appropriate related format.
The size of images can be reduced where needed to fit to smaller screens and text size is enlarged and menus change to a drop down system rather than horizontal system.
A better usage example of this would be in the case of a website that is optimized to suit mobile devices as well as desktop computers in which the links in the top menu would be more workable repositioned as a vertical list as compared to a horizontal bar going across. This related act of detail is supported by responsive web design.
Responsive web design is not to be confused with a dedicated mobile website. A dedicated mobile website which is hosted on a sub domain involves building a separate website specifically for mobile use and means extra cost to the client and even additional work for developers. The clients find themselves having to manage two unrelated sites and this does not genuinely negate the need for having a dedicated mobile website as some organisations may have different marketing policies or offer up a unique and different product or service for cell phone users.
If you have a grid in your layout where 10 thumbnails fit nicely across on a regular desktop computer monitor, then those thumbnails would have to be awful small to fit 10 across on an iPad or iPhone or some gadget with a smaller screen size. With a responsive design you can change it so that if the width of the device is as short as an iPad or iPhone, it only places 7 thumbnails across the screen depending on the resolution.
Responsive web design is a recent term that has been used to describe the concept of a website layout changing in response to the screen size and resolution of screen of user. This has grown in importance with the rise of various gadgets like smartphones and tablets because their screens are very different from those of traditional laptops and desktops.
Responsive web design is the term used for a website that changes and adapts its appearance for optimal viewing on all sized screens. It is sometimes referred to as adaptive webdesign. Sites that are not made responsive do not adapt to different screens and as such can be hard to view and navigate on small devices.
A lot of website contact forms are accompanied with a sidebar area for up sale and other purposes whichis great for a desktop computer but on a smart phone the form and the sidebar both are shrunken down too small to read which is by default. The form can be made to fill the screen and the sidebar can be hiddenwith responsive web design.