In the context of mobile devices, responsive design refers to the approach of creating websites and applications that adapt to various screen sizes and orientations. This technique ensures optimal viewing experiences across devices, from smartphones and tablets to desktops. Responsive design utilizes flexible grids, fluid images, and CSS media queries to adjust layouts automatically based on the device's characteristics. By improving user experience and accessibility, responsive design plays a critical role in increasing user engagement and retention. This approach is essential in today's digital landscape, where users access content across a multitude of devices.