Материал из википедия КГПА
The first attempt to allow use of content and basic functionality of a website and supply a professional version of the same site to browsers with better or more complete Web Standards support is known as Progressive Enhancement that was introduced in 2003. The corresponding approach is often referred to as graceful degradation. By making use of guidelines such as developing a correct document structure in the markup, web designers can contribute not only to Progressive Enhancement, but additionally Web Accessibility and overall code quality.
To supply the greatest level of interoperability and usability, websites should be developed by applying techniques that support an optimal consumer experience through device-, browser-, and/or feature-detection, so the website is going to be easy to navigate and read whatever the device used for browsing (smartphone, tablet computer, desktop PC, etc.). The text message from the website will not be tiny on a phone, and the large pictures is going to be automatically resized with respect to the display size and resolution.
Until recently, a large share of websites continues to be made with fixed width layout (typically between 760px and 960px) that may provide precise pixel-by-pixel representation, but cannot use the full the surface of today's large monitors. It also has serious usability issues around the increasingly popular mobile devices for example smartphones and pc tablets that include a relatively small display size and resolution. Even on standard resolutions, the consumer might use a resized (not maximized) browser window. The endless number of screen resolutions makes it practically infeasible to support all resolutions with a design that's optimized for a certain resolution.
In well-developed countries for example Australia, smartphone use is over 50% now which represents extraordinary growth in mobile technology. By 2014, more Australians will access digital services via a smartphone than the usual computer.
Among the approaches to address the issues of barely readable texts, inconsistent layout, and inconvenient scrollability is Responsive Web Design (RWD), which applies an adaptable grid layout that's scalable (also known as liquid layout or fluid layout). Responsive Web Design has the try to achieve optimal consumer experience in terms of convenient reading and simple navigation, and "respond" to device features. Depending on the characteristics of the device getting used, different layouts are used, along with automatically scaling website elements, including text and pictures. Since some website elements such as Flash headers containing raster graphics and videos cannot be fully optimized for automatic scaling, the applicability of Responsive Web Design depends upon the web site. If the reliable fixed-width layout is used for whatever reasons, support for cellular devices can still be supplied by creating additional, device-dependent style sheets.
Another approach, elastic layout applies fully scalable elements declared in scalable units within the style sheets, which is the most advanced yet seldom applied web design layouts.
Although RWD could be beneficial to mobile users, responsive websites are not necessarily accessible, and vica versa. However, the proper utilization of standards leads to websites which are accessible and responsive simultaneously.