A Content Delivery Network (CDN) functions by distributing content across multiple servers strategically placed around the globe. Its primary purpose is to improve the delivery speed and availability of web content to end-users. CDNs cache content like images, videos, and applications closer to users, minimizing latency and ensuring fast load times. They also provide load balancing, security features like DDoS protection, and enhance user experience by optimizing resource usage. Overall, CDNs are essential for managing high traffic volumes and maintaining reliable access to websites and online services.