Terminology

News Server

A server that stores newsgroups and articles and is responsible for the distribution of newly arrived articles. The news server itself has no caching or proxying functionality.

News Reader (Client)

The news reader is a program used to access news articles. The news client requests newsgroups and articles from the news server and presents these articles to its user and provides a user friendly interface.

News Feed

A news server that provides (feeds) newsgroups and articles to other news servers.

Leaf Node News Server

A leaf node news server is a news server being connected to only one other news server (to its only news feed). Thus a leaf node news server is not responsible to exchange news articles with many other news servers, but only exchanges news articles with its news feed.

Cache Server

A cache server speeds up requests to repeatedly requested objects. Whenever a request is done by a client, the Cache Server checks whether the requested data have already been cached by the News Cache. Otherwise the Cache Server retrieves the requested data from the original server and stores them locally. Then the requested data are sent to the client. Hence, successive requests to the same data reduce the required network bandwidth between the News Cache and the original server.

Proxy Server

A proxy server passes requests from its clients to another server and all answers being received from the server will be passed back to the proxy's clients. This configuration makes sense if a client cannot reach a given server directly (e.g., in case of a firewall). In this situation clients can make use of the service provided by the server indirectly via the proxy server. Frequently a cache and a proxy server are combined.

Global Newsgroups

Newsgroups are denominated as global, if they are accessible world-wide. This implies that the newsgroups are distributed to news servers that are part of different organizations.

Local Newsgroups

A newsgroup is called local, if it is not distributed to other news servers. This is useful if the newsgroup should provide a local discussion forum that may even contain sensitive data. Hence the newsgroup's articles must not be distributed to other news servers.