Usenet

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Usenet is a pioneering computador[1] network communication system, developed in 1980. It’s built on a framework known as UUCP, which allows mail exchange, file transfers, and public announcements. Usenet hosts vast amounts of data, organized into specific areas of interest called newsgroups, and further into threads created by article responses. Unlike other platforms, Usenet doesn’t require personal registration. It stores no information on a remote server, and its archives are always accessible. Users can connect to Usenet through various internet[2] service providers (ISPs) and news servers. While Usenet was initially associated with Unix, it has evolved to encompass all major operating systems.

Definições de termos
1. computador. Um computador é um dispositivo sofisticado que manipula dados ou informações de acordo com um conjunto de instruções, conhecidas como programas. Por conceção, os computadores podem executar uma vasta gama de tarefas, desde simples cálculos aritméticos até ao processamento e análise de dados complexos. Os computadores evoluíram ao longo dos anos, desde as primitivas ferramentas de contagem, como o ábaco, até às modernas máquinas digitais. O coração de um computador é a sua unidade central de processamento (CPU), que inclui uma unidade lógica aritmética (ALU) para efetuar operações matemáticas e registos para armazenar dados. Os computadores também têm unidades de memória, como ROM e RAM, para armazenar informação. Outros componentes incluem dispositivos de entrada/saída (E/S) que permitem a interação com a máquina e circuitos integrados que melhoram a funcionalidade do computador. As principais inovações históricas, como a invenção do primeiro computador programável por Charles Babbage e o desenvolvimento do primeiro computador eletrónico digital automático, o Atanasoff-Berry Computer (ABC), contribuíram grandemente para a sua evolução. Atualmente, os computadores alimentam a Internet, ligando milhares de milhões de utilizadores em todo o mundo, e tornaram-se uma ferramenta essencial em quase todas as indústrias.
2. internet. A Internet é um sistema global de redes informáticas interligadas que utilizam protocolos de comunicação normalizados, principalmente o TCP/IP, para ligar dispositivos em todo o mundo. Com origem no termo "internetted" utilizado em 1849, o termo "Internet" foi mais tarde utilizado pelo Departamento de Guerra dos EUA em 1945. O seu desenvolvimento começou com cientistas informáticos que criaram sistemas de partilha de tempo na década de 1960 e progrediu com a criação da ARPANET em 1969. A Internet é autónoma, sem uma autoridade central, e os seus principais espaços de nomes são administrados pela Internet Corporation for Assigned Names and Numbers (ICANN). Transformou significativamente os meios de comunicação tradicionais e tem crescido exponencialmente ao longo dos anos, com os utilizadores da Internet a aumentarem anualmente de 20% para 50%. Em 2019, mais de metade da população mundial utilizou a Internet. O conjunto de protocolos da Internet, que inclui o TCP/IP e quatro camadas conceptuais, orienta os pacotes da Internet para os seus destinos. Serviços essenciais como o correio eletrónico e a telefonia via Internet funcionam na Internet. A World Wide Web, uma coleção global de documentos interligados, é uma componente essencial da Internet.
Usenet (Wikipédia)

Usenet (/ˈjznɛt/), USENET, or, "in full", User's Network, is a worldwide distributed discussion system available on computers. It was developed from the general-purpose Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott e Jim Ellis conceived the idea in 1979, and it was established in 1980. Users read and post messages (called articles ou posts, and collectively termed news) to one or more topic categories, known as newsgroups. Usenet resembles a bulletin board system (BBS) in many respects and is the precursor to the Fóruns na Internet that have become widely used. Discussions are threaded, as with web forums and BBSes, though posts are stored on the server sequentially.

A 2004 discussion in the Usenet group comp.text.tex
A diagram of Usenet servers and clients. The coloured dots on the servers represent the newsgroups they carry. Coloured arrows between servers indicate newsgroup content exchanges (news feeds). Arrows between clients and servers indicate that a user is subscribed to a certain newsgroup and reads or submits articles there.

Notably, clients never connect with each other, but still have access to each other's posts even when they also never connect to the same server.

A major difference between a BBS or web message board and Usenet is the absence of a central server and dedicated administrator or hosting provider. Usenet is distributed among a large, constantly changing set of news servers that store and forward messages to one another via "news feeds". Individual users may read messages from and post to a local (or simply preferred) news server, which can be operated by anyone, and those posts will automatically be forwarded to any other news servers peered with the local one, while the local server will receive any news its peers have that it currently lacks. This results in the automatic proliferation of content posted by any user on any server to any other user subscribed to the same newsgroups on other servers.

As with BBSes and message boards, individual news servers or service providers are under no obligation to carry any specific content, and may refuse to do so for many reasons: a news server might attempt to control the spread of spam by refusing to accept or forward any posts that trigger spam filters, or a server without high-capacity data storage may refuse to carry any newsgroups used primarily for partilha de ficheiros, limiting itself to discussion-oriented groups. However, unlike BBSes and web forums, the dispersed nature of Usenet usually permits users who are interested in receiving some content to access it simply by choosing to connect to news servers that carry the feeds they want.

Usenet is culturally and historically significant in the networked world, having given rise to, or popularized, many widely recognized concepts and terms such as "FAQ", "flame", "sockpuppet", and "spam". In the early 1990s, shortly before access to the Internet became commonly affordable, Usenet connections via Fidonet's dial-up BBS networks made long-distance or worldwide discussions and other communication widespread, not needing a server, just (local) telephone service.

The name Usenet comes from the term "users' network". The first Usenet group was NET.general, which quickly became net.general. The first commercial spam on Usenet was from immigration attorneys Canter and Siegel advertising green card services.

On the Internet, Usenet is transported via the Network News Transfer Protocol (NNTP) on TCP Port 119 for standard, unprotected connections and on TCP port 563 for SSL encrypted connections.

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