Both responsive and adaptive design cater to mobile users. Responsive design uses flexible grids to adjust content fluidly. Adaptive design uses fixed layouts that change at specific breakpoints. Responsive is easier to manage with one codebase. Adaptive can be faster with tailored versions. Responsive adapts to any screen size, future-proofing your site. Adaptive offers more control over specific device experiences. Responsive tends to rank better in SEO. Adaptive may require more resources to build and maintain. Choose responsive for general websites with varied audiences. Adaptive suits highly targeted apps or devices. Both improve UX, but trade-offs differ. Testing is essential either way. Budget and timeline also play roles. Choose based on goals, not trends.