Until recent history, many of the more elegant websites were designed using similar skills to those used to design a typical poster or brochure. The idea was to get a website that would look the same on everyone's computer screen no matter which browser they were using. This idea was often referred to as Pixel Perfect design and it was well suited to an era where visitors to websites were, for the most part, visiting on computers with screens sizes were quite close to the same dimensions.
With the explosion of smart phones, tablets, netbooks, watches and various other electronics, websites today need to customize how they look to match the size of the device they're being viewed on. Some devices have small screens, some have big screens. Some are low resolution, some are high resolution. Most devices can support an array of browsers, making it very difficult to predict exactly how a website will display on thousands and thousands of different screen configurations.
The technology that has emerged and arguably handles the diversity of today's website visitors is called “responsive design
”. The concept is simple, create a website that will automatically reshape, reorganize and rescale content to match the needs of the visitor. The application is not so simple. Many website designers and website owners are used to the idea that a website should look exactly how they want it to look. Responsive design says that it's more important for a website to function well than to have a specific look. It's almost like a battle between the left brained programmer and the right brained designer. At the end of the day, the goal is to try and meet somewhere in the middle, combining the concepts of a nice design with the functional needs of thousands of devices so that whatever happens, the website visitor has a high probability of getting a website that displays the content nicely and is easily navigable.