CDNs significantly enhance SEO by improving website performance. They reduce load times, which is critical for Google’s Core Web Vitals and rankings. CDNs also lower server load, enhance mobile performance, and provide global benefits by reducing latency. Security features like DDoS protection and SSL encryption further support SEO trust signals. Common issues include duplicate content, incorrect geolocation, and caching problems; these can be resolved with canonical tags, geo-targeting settings, and proper cache-control headers. Best practices involve selecting the right CDN provider, optimizing caching, using SEO tools for performance monitoring, ensuring HTTPS, and combining CDNs with other speed optimizations. Regular testing and monitoring are essential to maintain SEO success.