Responsive web design (RWD) is a web design approach aimed at crafting sites to provide an optimal viewing experience—easy reading and navigation with a minimum of resizing, panning, and scrolling—across a wide range of devices (from mobile phones to desktop computer monitors).
A site designed with RWD adapts the layout to the viewing environment by using fluid, proportion-based grids, flexible images,and CSS3 media queries, an extension of the @media rule.
The fluid grid concept calls for page element sizing to be in relative units like percentages, rather than absolute units like pixels or points.
Flexible images are also sized in relative units, so as to prevent them from displaying outside their containing element.
Media queries allow the page to use different CSS style rules based on characteristics of the device the site is being displayed on, most commonly the width of the browser.
Server-side components (RESS) in conjunction with client-side ones such as media queries can produce faster-loading sites for access over cellular networks and also deliver richer functionality/usability avoiding some of the pitfalls of device-side-only solutions.
Audience and Device Aware (ADA)
Audience and Device Aware is an approach aimed at ensuring that a site is optimised to deliver what a user wants and that works effectively on the device being used to access the site. Unlike Responsive web design (RWD), which crafts a site visually for a range of devices, ADA aims to reflect the many different elements that enhance and impact on the performance and usability of a site. The predominant application for the ADA approach is for mobile and smaller screen devices. The principle truly sees the adoption of a “mobile first” strategy and focuses on the performance of a site and value that it delivers to a user and the business.