Content Delivery Networks (CDNs) are systems of distributed servers that deliver web content to users based on their geographic location. By caching content closer to users, CDNs reduce latency and improve load times, enhancing the overall user experience. CDNs are essential for websites with high traffic or global audiences, as they help manage bandwidth and ensure reliability. Major CDN providers, such as Akamai and Cloudflare, offer services that include not only content delivery but also security features like DDoS protection and SSL encryption.