Responsive Web design (RWD) is an approach to Web design that aims to provide an optimal viewing experience for every user, regardless of the context into which the Web page is loaded. This takes into account the multiplicity of devices commonly used to browse the Internet. Based on the concept of a fluid grid, RWD mainly focuses on the application of CSS. Flexible containers are defined that can shift position when a view screen passes predefined descriptions for small, medium, or large dimensions.