A Content Delivery Network (CDN) is a network of distributed servers strategically located in various data centers around the world. The primary purpose of a CDN is to deliver web content, such as text, images, videos, scripts, and other resources, to users more efficiently and reliably. CDNs are designed to improve the performance, availability, and security of websites and web applications.

CDNs play a crucial role in optimizing web content delivery by reducing latency, improving availability, enhancing security, and providing scalability for websites and web applications. They are a vital component of modern internet infrastructure, helping ensure a seamless and efficient user experience.