News server

A news server is a collection of software used to handle Usenet articles. It may also refer to a computer itself which is primarily or solely used for handling Usenet. Access to Usenet is only available through news server providers. End users often use the term "posting" to refer to a single message or file posted to Usenet. For articles containing plain text, this is synonymous with an article. For binary content such as pictures and files, it is often necessary to split the content among multiple articles. Typically through the use of numbered Subject: headers, the multiple-article postings are automatically reassembled into a single unit by the newsreader. Most servers do not distinguish between single and multiple-part postings, dealing only at the level of the individual component articles. Each news article contains a complete set of header lines, but in common use the term "headers" is also used when referring to the News Overview database. The overview is a list of the most frequently used headers, and additional information such as article sizes, typically retrieved by the client software using the NNTP command. Overviews make reading a newsgroup faster for both the client and server by eliminating the need to open each individual article to present them in list form. If non-overview headers are required, such as for when using a , it may still be necessary to use the slower method of reading all the complete article headers. Many clients are unable to do this, and limit filtering to what is available in the summaries. Among the operators and users of commercial news servers, common concerns are the continually increasing storage and network capacity requirements and their effects. Completion (the ability of a server to successfully receive all traffic), retention (the amount of time articles are made available to readers) and overall system performance. With the increasing demands, it is common for the transit and reader server roles to be subdivided further into numbering, storage and front end systems.