A Usenet newsgroup is a repository usually within the Usenet system for messages posted from users in different locations using the Internet. They are not only discussion groups or conversations, but also a repository to publish articles, start developing tasks like creating Linux, sustain mailing lists and file uploading. That’s thanks to the protocol, which has no article size limit - it’s up to the providers to decide. In the late 1980s, Usenet articles were often limited by the providers to 60,000 characters, but in time, Usenet groups have been split into two types: text for mainly discussions, conversations, articles, limited by most providers to about 32,000 characters, and binary for file transfer, with providers setting limits ranging from less than 1 MB to about 4 MB. Newsgroups are technically distinct from, but functionally similar to, discussion forums on the World Wide Web. Newsreader software is used to read the content of newsgroups. Before the adoption of the World Wide Web, Usenet newsgroups were among the most popular Internet services.
Communication is facilitated by the Network News Transfer Protocol (NNTP) which allows connection to Usenet servers and data transfer over the internet. Similar to another early (yet still used) protocol SMTP which is used for email messages, NNTP allows both server-server and client-server communication. This means that newsgroups can be replicated from server to server which gives the Usenet network the ability to maintain a level of robust data persistence as a result of built-in data redundancy. However, most users will access using only the client-server commands of NNTP and in almost all cases will use a GUI for browsing as opposed to command line based client-server communication specified in the NNTP protocol.
