They differ from chat rooms in that messages are often longer than one line of text, and are at least temporarily archived. Also, depending on the access level of a user or the Forum setup, a posted message might need to be approved by a moderator before it becomes publicly visible.
Forums have a specific set of jargon associated with them; for example, a single conversation is called a "thread", or topic.
A discussion forum is hierarchical or tree-like in structure; a forum can contain several subforums, each of which may have several topics. Within a forum's topic, each new discussion is called a thread and can be replied to by as many people as they wish.
Depending on the forum's settings, users can be anonymous or have to register with the forum and then subsequently log in to post messages. Users do not have to log in to read existing threads on most forums.
The modern forum originated from bulletin boards and so-called computer conferencing systems, a technological evolution of the dial-up bulletin board systems (BBS). From a technological standpoint, forums or boards are web applications that manage user-generated content.
Early internet forums could be described as a web version of an electronic mailing list or newsgroup (such as those that exist on Usenet), allowing people to post messages and comment on other threads. Later developments emulated the different newsgroups or individual lists, providing more than one forum dedicated to a particular topic.
Internet forums are prevalent in several developed countries. Japan posts the most, with over two million per day on their largest forum, 2channel. China also has millions of posts on forums such as Tianya Club.
Some of the first forum systems were the Planet-Forum system, developed at the beginning of the 1970s; the EIES system, first operational in 1976; and the KOM system, first operational in 1977.
One of the first forum sites (which is still active today) is Delphi Forum, once called Delphi. The service, with four million members, dates to 1983.
Forums perform a function similar to that of dial-up bulletin board systems and Usenet networks that were first created in the late 1970s. Early web-based forums date back as far as 1994, with the WIT project from the W3 Consortium, and starting at this time, many alternatives were created. A sense of virtual community often develops around forums that have regular users.
are popular areas for forum themes, but there are forums for a huge number of topics. Internet slang and image macros popular across the internet are abundant and widely used in internet forums.
Forum software packages are widely available on the internet and are written in a variety of programming languages, such as PHP, Pearl, Java, and ASP. The configuration and records of posts can be stored in text files or a Database. Each package offers different features, from the most basic, providing text-only postings, to more advanced packages, offering multimedia support and formatting code (usually known as BBCode). Many packages can be integrated easily into an existing website to allow visitors to post comments on articles.
Several other web applications, such as blog software, also incorporate forum features. WordPress comments at the bottom of a blog post allow for a single-threaded discussion of any given blog post. Slashcode, on the other hand, is far more complicated, allowing full threaded discussions and incorporating a robust moderation and meta-moderation system as well as many of the profile features available to forum users.
Some stand-alone threads on forums have reached fame and notability, such as the "I am lonely Will anyone speak to me" thread on MovieCodec.com's forum, which was described as the "web's top hangout for lonely folk" by Wired Magazine.
A forum consists of a tree-like directory structure. The top end is "Categories". A forum can be divided into categories for the relevant discussions. Under the categories are sub-forums, and these sub-forums can further have more sub-forums. The topics (commonly called threads) come under the lowest level of sub-forums, and these are the places under which members can start their discussions or posts.
Logically, forums are organized into a finite set of generic topics (usually with one main topic), driven and updated by a group known as members, and governed by a group known as moderators. It also can have a graph structure. All message boards will use one of three possible display formats. Each of the three basic message board display formats:
has its own advantages and disadvantages.
If messages are not related to one another at all, a Non-Threaded format is best. If a user has a message topic and multiple replies to that message topic, a semi-threaded format is best. If a user has a message topic and replies to that message topic and responds to replies, then a fully-threaded format is best.
Forums prefer the premise of open and free discussion and often adopt de facto standards. The most common topics on forums include;
It is not uncommon for nonsense or unsocial behavior to sprout as people lose their temper, especially if the topic is controversial. Poor understanding of the difference in values among the participants is a common problem on forums. Because replies to a topic are often worded to target someone's point of view, a discussion will usually go slightly off in several directions as people question each other's validity, sources, and so on. Circular discussion and ambiguity in replies can extend for several tens of posts in a thread, eventually ending when everyone gives up or attention spans waver and a more interesting subject takes over. It is not uncommon for debate to end in ad hominem attacks.
Several lawsuits have been brought against the forums and moderators, claiming libel and damage. A recent case in the Scubaboard lawsuit, where a Business in the Maldives filed a suit against Scubaboard for libel and defamation in Jan 2010.
For the most part, though, forum owners and moderators in the United States are protected by Section 230 of the Communications Decency Act, which states that "no provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider".
In 2019, Facebook was faced with a class action lawsuit set forth by moderators diagnosed with post-traumatic stress disorder. It was settled for $52 million the following year.