Content Delivery Networks (CDNs) enhance the delivery of content across multiple regions by distributing it through a network of globally located Points of Presence (PoPs) and edge servers, reducing latency and improving performance. Their architecture includes edge, mid, and core tiers, enabling efficient caching and traffic routing. CDNs use intelligent caching strategies, consistency models, DNS-based routing, and Anycast to optimize content delivery dynamically. They also support TCP and HTTP/3 optimizations and extend security with DDoS protection, WAFs, and compliance features. Challenges include balancing content freshness with performance, cost management, and regional infrastructure differences. Advancements in edge computing, machine learning, and hybrid solutions are expected to further improve global content delivery.