The TCP/IP Guide  9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)       9  TCP/IP Key Applications and Application Protocols            9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)                 9  Usenet (Network News) and the TCP/IP Network News Transfer Protocol (NNTP)                      9  Usenet Overview, Concepts and General Operation

Usenet Overview, History and Standards 1 2 3 Usenet Addressing: Newsgroups, Newsgroup Hierarchies and Types

When the students at Duke University decided to create their online community, electronic mail was already in wide use, and there were many mailing lists in operation as well. E-mail was usually transported using UUCP during these pre-Internet days, the same method that Usenet was designed to employ. The obvious question then was, why not simply use e-mail to communicate between sites?

The main reason is that e-mail is not really designed to facilitate the creation of an online community where information can be easily shared in a group. The main issue with e-mail in this respect is that only the individuals who are specified as recipients of a message can read it. There is no facility whereby someone can write a message and put it in an open place where anybody who wants can read it, analogous to posting a newsletter in a public place.

Another problem with e-mail in large groups is related to efficiency: if you put 1,000 people on a mailing list, each message sent to that list must be duplicated and delivered 1,000 times. Early networks were limited in bandwidth and resources; using e-mail for wide-scale group communication was possible, but far from ideal.

To avoid the problems of using e-mail for group messaging, Usenet was designed using a rather different communication and message-handling model than e-mail. The defining difference between the Usenet communication model and that used for e-mail is that Usenet message handling is oriented around the concept of public distribution, rather than private delivery to an individual user. This affects every aspect of how Usenet communication works:

• Addressing: Messages are not addressed from a sender to any particular recipient or set of recipients, but rather to a group, which is identified with a newsgroup name.
  
  
• Storage: Messages are not stored in individual mailboxes but in a central location on a server, where any user of the server can access them.
  
  
• Delivery: Messages are not conveyed from the sender's system to the recipient's system, but are rather spread over the Internet to all connected systems so anyone can read them.

Usenet Overview, History and Standards 1 2 3 Usenet Addressing: Newsgroups, Newsgroup Hierarchies and Types