A responsive website is a website that is designed to adapt to different screen sizes, orientations, layouts, and platforms to ensure usability and satisfaction. Responsive web design (RWD) is an approach to web design that aims to make web pages render well on a variety of devices and window or screen sizes from minimum to maximum display size. This is accomplished with the use of flexible grids and layouts, responsive images, and CSS media queries. The key features of a responsive website include:

• Fluid Grids: Page element sizing is in relative units like percentages, rather than absolute units like pixels or points.

• Flexible Images: Images are automatically resized to fit the screen size.

• CSS3 Media Queries: CSS media queries are used to apply different styles to different devices based on their screen size, orientation, resolution, color capability, and other characteristics.

Responsive web design became more important as users of mobile devices came to account for the majority of website visitors. Responsive web design is an example of user interface plasticity. It eliminates the need for a different design and development phase for each new gadget on the market. Responsive web design can also boost a sites SEO performance and create a better user experience for people who browse the internet on their phones.