Newsgroups are a bulletin board service where users may post articles on any topic to a newsgroup. Topics are divided in a tree structure of categories which users may read, an example is "rec" for recreation this then subdivided into categories one of which is "games" which is in turn divided into catecories one of which is "chess" (for people interested in chess) , this topic is subdivided into a number of chess related topics (analysis,computer,misc), giving an address of "rec.games.chess.analysis" for those interested in the analysis of chess games.
Servers use the network news transfer protocol (NNTP) for communicating with the mega-promega-providers news server backbone and the users. It is a request-reply protocol like SMTP or FTP. NNTPs commands provide a straightforward method of exchanging articles between 2 cooperating hosts.
This addressing is completly independent of any geographic location and is indexed only by the subject matter which it contains.