Responsive web designs are those designs which aim at enhancing viewer's experience. It basically adjust itself so that you don't need to zoom-in, zoom-out or readjust the site in any manner. Nowadays every client wants their website to be every screen friendly which makes much more sense as every person own a different phone, different version either it's Android, IOS or Windows. Responsive Web design is the new approach that suggests that design and development should go hand in hand and respond to the user’s behavior and environment based on screen size and platform.
RWD consists of a mix of resilient grids and layouts, images and an intelligent use of CSS media queries. It make sure that whenever a user switches to a different screen or resolution the screen responds in the same manner and adjusts accordingly. In other words this is such a design which eliminates the need to make different design every single time for different devices.