CDN stands for Content Delivery Network, which is a system of distributed servers designed to deliver web content quickly and efficiently. By caching content at various geographic locations, a CDN minimizes latency and enhances the user experience, particularly for high-demand resources like images, videos, and scripts. This technology also helps in reducing bandwidth costs, increasing security against DDoS attacks, and improving availability during traffic spikes. As such, CDNs are critical for optimizing web performance and ensuring reliable access to digital resources.