A Content Distribution Network (CDN) is a system 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 loading times for websites and applications. This is especially important for media-rich content like videos and images. CDNs also enhance website reliability and security. They can handle large amounts of traffic, ensuring that websites remain accessible even during peak usage. Additionally, CDNs often provide protection against DDoS attacks and other security threats, making them a vital component of modern web infrastructure.