Content Delivery Networks (CDNs) provide a global network of servers across a wide range of geographical locations. That way users can connect to a server that’s close to them, reducing round trip times. Often the CDN will also serve cached responses, which means no request to the origin server is required. Let’s assume a fast wifi connection and a CDN location (or edge node) that’s close to the user. A network round trip might just take 10 milliseconds and a full HTTP including establishing a connection would take just 40 milliseconds.