A server is a computer hardware device that provides computing and storage resources to serve websites and applications on the Internet. CDN is an acceleration service based on a distributed network. It uses server nodes located all over the world to distribute the content of websites and applications to the nodes closest to users, thereby improving access speed and stability.

Then, how does the server work on the CDN? A CDN usually consists of multiple server nodes located all over the world. When users request content, they will automatically connect to the nearest node for access. When a user requests the content of a certain website, the CDN will first determine whether the content has been cached on the node, and if so, return the data directly from the node; if not, obtain the data from the source server and cache it to the node for faster access the next time the user requests it.

Therefore, the principle of CDN using servers for cache acceleration is to deploy node servers all over the world and cache the content on the source server to the nodes, so that users can obtain data from the nearest node, thereby improving access speed and stability.

The relationship between the CDN node server and the source server is:

1. The CDN node server is an edge server that maps website content, and can provide users with website content stored in the server closest to them according to their geographical location.

2. The source server is the original data storage server of the website, responsible for providing content updates and back-to-source requests to the CDN node server.

3. Intelligent scheduling is performed between the CDN node server and the source server through global load balancing and regional load balancing equipment, so that users can access the optimal node.

4. The storage content of the CDN node needs to be regularly and purposefully updated between the CDN node server and the source server, so as to facilitate users to read the cached content.