A responsive web layout is a way to make sure that your website displays properly and elegantly on any browser window size. A responsive layout will rearrange or resize elements on the page to best fit the size of window in which the website is being displayed. Because your visitors will be using a variety of screen sizes and resolutions, you want to be sure that your site displays as intended and that all of your content is visible.
By viewing your website layout as it was intended to be displayed, visitors will have an easier time finding the relevant information they are looking for as well as enjoying a superior browsing experience which will reflect positively on your company and brand. The aesthetics of your layout will be greatly enhanced if columns and content can be rearranged to best suit the dimensions of the window or device that your visitors are using.
Vast improvements have been made in responsive web design with the advent of CSS and HTML5. It is almost rare to discover modern sites that are not responsive. This has allowed companies to use a single site that will display better across all devices and results in better search rankings, robust usability, and most importantly fewer headaches for the developers making the site.