Editing Usenet newsgroup (section)

==Types==
{{anchor|Types of newsgroups}}
Newsgroups generally come in either of two types, binary, with single messages limited to some MB's, or text, where text groups are limited to some tens of kilobytes. There is no technical difference between the two, but the naming differentiation allows users and servers with limited facilities to minimize network bandwidth usage, by dropping the large size binary groups. Historically, with [[Modem|telephone modems]] at only kilobytes transfer rates, Usenet conventions and rules were enacted to minimize the overall amount of network traffic and resource usage, but today, only the above message size hard limits imposed by the providers are respected.

Typically, the newsgroup is focused on a particular topic of interest<!-- such as "animal husbandry," "pole vaulting," or "glockenspiel MIDI files"-->. A message sent for publication on a newsgroup is called a "post". Some newsgroups allow posts on a wide variety of themes, regarding anything a member chooses to discuss as [[on-topic]], while others keep more strictly to their particular subject, frowning on [[off-topic]] posts. The news admin (the administrator of a [[news server]]) decides how long posts are kept on their server before being expired (deleted), which is called [[Usenet#Binary retention time|retention]]. Different servers will have different retention times for the same newsgroup; some may keep posts for as little as one or two weeks, others may hold them for many years.

Back when the early community was the pioneering computer society, the common habit seen with many posts was a notice at the end that disclosed whether the author had (or was free of) a personal interest (financial, political or otherwise) in making the post. This is rarer now, and the posts must be read more skeptically, as with other media. Privacy and [[phishing]] issues have also risen in importance.

Usenet newsgroups posters and operators usually do not make money from their occupations on the platform.

The number of newsgroups grew from more than 100 as of 1983<ref name="emerson198310">{{cite news | url=https://archive.org/stream/byte-magazine-1983-10/1983_10_BYTE_08-10_UNIX#page/n219/mode/2up | title=Usenet / A Bulletin Board for Unix Users | work=BYTE | date=October 1983 | access-date=31 January 2015 | author=Emerson, Sandra L. | pages=219–236}}</ref> to more than 110,000, but only 20,000 or so of those are active.<ref>{{Cite web |title=List of Active Newsgroups |url=https://www.tech-insider.org/internet/research/1988/1230.htm |access-date=2024-12-20 |website=www.tech-insider.org}}</ref> Newsgroups vary in popularity; some newsgroups receive fewer than a dozen posts per year while the most popular can get several thousand in under an hour.

===Binary===
[[File:Usenet-total-storage.jpg|thumb|300px|October 2020 screenshot showing 60 PB of usenet group data<ref>{{cite web|url=https://www.binsearch.info/groupinfo.php |title=Usenet storage is more than 60 petabytes (60000 terabytes) |publisher=binsearch.info |access-date=October 20, 2020 |archive-url=https://archive.today/20200521133653/https://www.binsearch.info/groupinfo.php |archive-date=2020-05-21 |url-status=live}}</ref>]]
While newsgroups were not created with the intention of distributing files such as pictures, sound and video, they have proven to be quite effective for this. As of 2022, some remain popular as an alternative to [[BitTorrent]] to share and download files.<ref>{{Cite web |last=Gregersen |first=Erik |last2=Hosch |first2=William L. |date=2022-02-17 |title=newsgroup |url=https://www.britannica.com/technology/newsgroup |access-date=2023-04-28 |publisher=[[Encyclopedia Britannica]] |language=en}}</ref>

Because newsgroups are widely distributed, a file uploaded once will be spread to many other servers and can then be downloaded by an unlimited number of users. More useful is that users download from a local news server, rather than from a more distant machine with perhaps limited connectivity, as may be the case with [[peer-to-peer]] technology. In fact, this is another benefit of newsgroups: it is usually not expected that users share. If every user makes uploads then the servers would be flooded; thus it is acceptable and often encouraged for users to just [[leech (computing)|leech]].

There were originally a number of obstacles to the transfer of binary files over Usenet. Usenet was originally designed with the transmission of text in mind, and so the encoding of posts caused losses in binary data where the data was not part of the protocol's [[character set]]. Consequently, for a long while, it was impossible to send binary data as such. As workarounds, [[codec]]s such as [[Uuencode]] and later [[Base64]] and [[yEnc]] were developed which encoded the binary data from the files to be transmitted (e.g. sound or video files) to text characters which would survive transmission over Usenet. At the receiver's end, the data needed to be decoded by the user's [[news client]].

Additionally, there was a limit on the size of individual posts so that large files could not be sent as single posts. To get around this, Newsreaders were developed which were able to split long files into several posts. Intelligent newsreaders at the other end could then automatically group such split files into single files, allowing the user to easily retrieve the file. These advances have meant that Usenet is used to send and receive many [[terabytes]] of files per day.

There are two main issues that pose problems for transmitting large files over newsgroups. The first is [[completion rate]]s and the other is [[retention rate]]s. The business of premium [[news server]]s is generated primarily on their ability to offer superior completion and retention rates, as well as their ability to offer very fast connections to users. Completion rates are significant when users wish to download large files that are split into pieces; if any one piece is missing, it is impossible to successfully download and reassemble the desired file. To work around the problem, a redundancy scheme known as [[Parchive]] (PAR) is commonly used.

Many major [[News server|news servers]] have a retention time of more than seven years.<ref>{{cite web|url=http://www.newsdemon.com/blog/retention-increase-to-2600-days-at-newsdemon/ |title=Retention Increase to 2600 Days at NewsDemon |date=28 September 2015 |publisher=Newsdemon.com |access-date=April 10, 2016}}</ref> A number of websites exist to keep an index of files posted to binary newsgroups.

Partly because of such long retention times, as well as growing [[upload]]ing and [[download]]ing speeds, Usenet is also used by individuals to store [[backup]] data in a practice called ''Usenet backup'', or uBackup.<ref>{{cite web|url=http://www.wikihow.com/Backup-Your-Data-on-Usenet-%28Ubackup%29 |title=usenet backup (uBackup) |publisher=Wikihow.com |access-date=February 14, 2012}}</ref> While commercial providers offer [[ease of use|easier-to-use]] [[List of online backup services|online backup services]], storing data on Usenet is free of charge (although access to Usenet itself may not be). A user must [[Backup#Data repository models|manually select, prepare and upload the data]]. Because anyone can download the backup files, the data is typically [[encryption|encrypted]]. After the files are uploaded, the uploader has no control over them; they are automatically distributed to all Usenet providers that subscribe to the newsgroup they are uploaded to, so there will be copies of them spread all around the world.

=== Moderated newsgroups ===
Most Newsgroups are not moderated. A moderated newsgroup has one or more individuals who must approve posts before they are published. A separate address is used to submit posts and the moderators then propagate those they approve of. The first moderated newsgroups appeared in 1984 under mod.* according to [[RFC 2235]], "Hobbes' Internet Timeline".