Wikipedia (// (listen), // (listen) WIK-ih-PEE-dee-ə) is a multilingual, web-based, free-content encyclopedia project supported by the Wikimedia Foundation and based on a model of openly editable content. The name is a portmanteau of the words wiki (a technology for creating collaborative websites, from the Hawaiian word wiki, meaning "quick") and encyclopedia.'s articles provide links designed to guide the user to related pages with additional information.
is written collaboratively by largely anonymous volunteers who write without pay. Anyone with Internet access can write and make changes to articles, except in limited cases where editing is restricted to prevent disruption or vandalism. Users can contribute anonymously, under a pseudonym, or, if they choose to, with their real identity. The fundamental principles by which operates are the five pillars. The community has developed many policies and guidelines to improve the encyclopedia; however, it is not a formal requirement to be familiar with them before contributing.
Since its creation on January 15, 2001, Wikipedia has grown rapidly into one of the largest reference websites, attracting 374 million unique visitors monthly as of September 2015[update]. There are about working on more than 48,000,000 articles in 302 languages. As of today, there are 5,995,408 articles in English. Every day, hundreds of thousands of visitors from around the world collectively make tens of thousands of edits and create thousands of new articles to augment the knowledge held by the Wikipedia encyclopedia. (See the statistics page for more information.) People of all ages, cultures and backgrounds can add or edit article prose, references, images and other media here. What is contributed is more important than the expertise or qualifications of the contributor. What will remain depends upon whether the content is free of copyright restrictions and contentious material about living people, and whether it fits within's policies, including being verifiable against a published reliable source, thereby excluding editors' opinions and beliefs and unreviewed research. Contributions cannot damage because the software allows easy reversal of mistakes and many experienced editors are watching to help ensure that edits are cumulative improvements. Begin by simply clicking the Edit link at the top of any editable page!
is a live collaboration differing from paper-based reference sources in important ways. Unlike printed encyclopedias, is continually created and updated, with articles on historic events appearing within minutes, rather than months or years. Because everybody can help improve it, has become more comprehensive than any other encyclopedia. In addition to quantity, its contributors work on improving quality as well. is a work-in-progress, with articles in various stages of completion. As articles develop, they tend to become more comprehensive and balanced. Quality also improves over time as misinformation and other errors are removed or repaired. However, because anyone can click "edit" at any time and add content, any article may contain undetected misinformation, errors, or vandalism. Awareness of this helps the reader to obtain valid information, avoid recently added misinformation (see Wikipedia:Researching with), and fix the article.
Wikipedia was founded as an offshoot of Nupedia, a now-abandoned project to produce a free encyclopedia, begun by the online media company Bomis. Nupedia had an elaborate system of peer review and required highly qualified contributors, but the writing of articles was slow. During 2000, Jimmy Wales (founder of Nupedia and co-founder of Bomis), and Larry Sanger, whom Wales had employed to work on the encyclopedia project, discussed ways of supplementing Nupedia with a more open, complementary project. Multiple sources suggested that a wiki might allow members of the public to contribute material, and Nupedia's first wiki went online on January 10, 2001.
There was considerable resistance on the part of Nupedia's editors and reviewers to the idea of associating Nupedia with a website in the wiki format, so the new project was given the name and launched on its own domain,.com, on January 15 (now called "Day" by some users). The bandwidth and server (in San Diego) were donated by Wales. Other current and past Bomis employees who have worked on the project include Tim Shell, one of the cofounders of Bomis and its current CEO, and programmer Jason Richey.
In May 2001, a large number of non-Englishs were launched—in Catalan, Chinese, Dutch, Esperanto, French, German, Hebrew, Italian, Japanese, Portuguese, Russian, Spanish, and Swedish. These were soon joined by Arabic and Hungarian. In September, Polish was added, and further commitment to the multilingual provision of was made. At the end of the year, Afrikaans, Norwegian, and Serbo-Croatian versions were announced.
The domain was eventually changed to the present.org when the not-for-profit Wikimedia Foundation was launched, in 2003, as its new parent organization, with the ".org" top-level domain denoting its non-commercial nature. Today, there ares in over 250 languages.
Anyone with Web access can edit, and this openness encourages inclusion of a tremendous amount of content. About 70,000 editors—from expert scholars to casual readers—regularly edit, and these experienced editors often help to create a consistent style throughout the encyclopedia, following our Manual of Style.
Several mechanisms are in place to help members carry out the important work of crafting a high-quality resource while maintaining civility. Editors are able to watch pages and technically skilled persons can write editing programs to keep track of or rectify bad edits. Where there are disagreements on how to display facts, editors often work together to compile an article that fairly represents current expert opinion on the subject. Aspiring authors may wish to read the information on Contributing to before contributing to the project.
Although the Wikimedia Foundation owns the site, it is largely uninvolved in writing and daily operations.
Most of's text and many of its images are dual-licensed under the Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA) and the GNU Free Documentation License (GFDL) (unversioned, with no invariant sections, front-cover texts, or back-cover texts). Some text has been imported only under CC-BY-SA and CC-BY-SA-compatible license and cannot be reused under GFDL; such text is identified either on the page footer, in the page history or on the discussion page of the article that utilizes the text. Every image has a description page that indicates the license under which it is released or, if it is non-free, the rationale under which it is used.
Contributions remain the property of their creators, while the CC-BY-SA and GFDL licenses ensure the content is freely distributable and reproducible. (See content disclaimer for more information.)
Text on is a collaborative work, and the efforts of individual contributors to a page are recorded in that page's history, which is publicly viewable. Information on the authorship of images and other media, such as sound files, can be found by clicking on the image itself or the nearby information icon to display the file page, which includes the author and source, where appropriate, along with other information.
|Readers' FAQ and help|
Many visitors come to to acquire knowledge, while others come to share knowledge. At this very instant, dozens of articles are being improved, and new articles are also being created. Changes can be viewed at the Recent changes page and a random page at random articles. Over 5,600 articles have been designated by the community as featured articles, exemplifying the best articles in the encyclopedia. Another 30,000 articles are designated as good articles. Some information on is organized into lists; the best of these are designated as featured lists. also has portals, which organize content around topic areas. Articles can be found using the search box on the top-right side of the screen.
is available in languages other than English. has more than two hundred and eighty languages, including a Simple English version, and related projects include a dictionary, quotations, books, manuals, and scientific reference sources, and a news service (see sister projects). All these are maintained, updated, and managed by separate communities, and often include information and articles that can be hard to find through other common sources.
articles are all linked, or cross-referenced. When highlighted text like this is seen, it means there is a link to some relevant article or page with further in-depth information. Holding the mouse over the link will often show to where the link will lead. There are other links towards the ends of most articles, for other articles of interest, relevant external websites and pages, reference material, and organized categories of knowledge which can be searched and traversed in a loose hierarchy for more information. Some articles may also have links to dictionary definitions, audio-book readings, quotations, the same article in other languages, and further information available on our sister projects. Additional links can be easily made if a relevant link is missing—this is one simple way to contribute.
As wiki documents, articles are never considered complete and may be continually edited and improved. Over time, this generally results in an upward trend of quality and a growing consensus over a neutral representation of information.
Users should be aware that not all articles are of encyclopedic quality from the start: they may contain false or debatable information. Indeed, many articles start their lives as displaying a single viewpoint; and, after a long process of discussion, debate, and argumentation, they gradually take on a neutral point of view reached through consensus. Others may, for a while, become caught up in a heavily unbalanced viewpoint which can take some time—months or years perhaps—to achieve a better balanced coverage of their subject. In part, this is because editors often contribute content in which they have a particular interest and do not attempt to make each article they edit comprehensive. However, eventually, additional editors expand and contribute to articles and strive to achieve balance and comprehensive coverage. In addition, operates a number of internal resolution processes that can assist when editors disagree on content and approach. Usually, editors eventually reach a consensus on ways to improve the article.
The ideal article is well written, balanced, neutral, and encyclopedic, containing comprehensive, notable, verifiable knowledge. An increasing number of articles reach this standard over time, and many already have. Our best articles are called Featured Articles (and display a small star in the upper right corner of the article), and our second best tier of articles are designated Good Articles. However, this is a process and can take months or years to be achieved through the concerted effort of editors. Some articles contain statements which have not yet been fully cited. Others will later be augmented with new sections. Some information will be considered by later contributors to be insufficiently founded and, therefore, may be removed.
While the overall trend is toward improvement, it is important to use carefully if it is intended to be used as a research source, since individual articles will, by their nature, vary in quality and maturity. Guidelines and information pages are available to help users and researchers do this effectively, as is an article that summarizes third-party studies and assessments of the reliability of.
has advantages over traditional paper encyclopedias. First, it is not limited in space: it can keep growing as fast as people add to it.
Second, there are no qualifications required to be able to author its articles. Therefore, it has a very large pool of contributors: the whole world. This, and the first advantage mentioned above, have enabled to become the most comprehensive encyclopedia on Earth.
Third, a paper encyclopedia remains static (stays the same) and falls out of date until the next edition. But is dynamic: you don't have to wait for the next edition to come out (there are no editions), as is published on-line as it is written on-line. Articles are made available as is, regardless of what stage of development they are in. You can update at any instant, and people do so continually around the clock, thereby helping each other to keep abreast of the most recent events everywhere and of the latest facts in every subject.
Fourth, has a very low "publishing" cost for adding or expanding entries, as it is on-line, with no need to buy paper or ink for distribution. This has allowed it to be made available for free, making it more accessible to everyone. This has enabled to be independently developed and published in many different languages at the same time, by people literate in each language. Of the 290+ different languages, 137 of them have 10,000 or more articles.
Sixth, is extra-linear (more than linear). Instead of in-line explanations, incorporates hypertext in the form of wikilinks. Throughout its content is a robust network of links, providing another dimension of knowledge accessibility. The encyclopedia also has correlates to tables of contents and indexes, with each entry in them hyperlinked to an article on the topic specified.
Seventh, each article provides an introduction summarizing the more extensive detail of its contents.
Eighth, being open to anyone to edit, articles on are subject to additions that might be erroneous or written poorly, which in turn are subject to being corrected or rewritten. It is a community effort, with most people who are involved helping to improve the work, fixing problems they encounter along the way. See more about's strengths and weaknesses, below ...
Wikipedia's greatest strengths, weaknesses, and differences all arise because it is open to anyone, it has a large contributor base, and its articles are written by consensus, according to editorial guidelines and policies.
The MediaWiki software that runs retains a history of all edits and changes, thus information added to never "vanishes" irreversibly. Discussion pages are an important resource on contentious topics. Therefore, serious researchers can often find a wide range of vigorously or thoughtfully advocated viewpoints not present in the consensus article. As with any source, information should be checked. A 2005 editorial by a BBC technology writer comments that these debates are probably symptomatic of cultural changes that are happening across all sources of information (including search engines and the media), and may lead to "a better sense of how to evaluate information sources".
disclaimers apply to all pages on. However, the consensus in is to put all disclaimers only as links and at the end of each article. Proposals to have a warning box at the beginning have been rejected. Some do not like the way it looks or that it calls attention to possible errors in.
Wikipedia, in common with many websites, has a disclaimer that, at times, has led to commentators citing these in order to support a view that is unreliable. A selection of similar disclaimers from places which are often regarded as reliable (including sources such as Encyclopædia Britannica, Associated Press, and the Oxford English Dictionary) can be read and compared at Wikipedia:Non-disclaimers.
Anyone can contribute to by clicking on the Edit tab in an article. Before beginning to contribute, however, read some handy helping tools such as the tutorial and the policies and guidelines, as well as our welcome page. offers many benefits. It is important to realize that in contributing to, users are expected to be civil and neutral, respecting all points of view, and add only verifiable and factual information rather than personal views and opinions. "The five pillars of" cover this approach and are recommended reading before editing. (Vandals are reported via the Administrator Notice Board and may be temporarily blocked from editing.)
Most articles start as stubs, but after many contributions, they can become featured articles. Once the contributor has decided a topic of interest, they may want to request that the article be written (or they could research the issue and write it themselves). has on-going projects, focused on specific topic areas or tasks, which help coordinate editing.
The ease of editing results in many people editing. That makes the updating of the encyclopedia very quick, almost as fast as news websites.
uses a simple yet powerful page layout to allow editors to concentrate on adding material rather than page design. Page aspects facilitated include:
Normally editing is chosen by clicking the Edit tab at the top of a page (or on a section-edit link). This will take you to a new page with a text box containing the editable text of the page you were viewing. In this box, you can type in the text that you want to add, using wiki markup to format the text and add other elements like images and tables. You should then press the Show preview button to review your contributions for any errors. When you have finished editing, you should write a short edit summary in the small field below the edit-box describing your changes before you press the Publish changes button. This will help others to understand the intention of your edit. To avoid accidentally leaving edit summaries blank, you can select "Prompt me when entering a blank edit summary" on the Edit tab of your personal preferences.
Page editing is accessed through tabs that are found along the top edge of the page. These are:
has robust version and reversion controls. This means that poor-quality edits or vandalism can quickly and easily be reversed or brought up to an appropriate standard by any other editor, so inexperienced editors cannot accidentally do permanent harm if they make a mistake in their editing. As there are many more editors intent on improving articles than not, error-ridden articles are usually corrected promptly.
|Core content policies|
|Other content policies|
content is intended to be factual, notable, verifiable with cited external sources, and neutrally presented.
The appropriate policies and guidelines for these are found at:
The community is largely self-organising, so that anyone may build a reputation as a competent editor and become involved in any role s/he may choose, subject to peer approval. Individuals often will choose to become involved in specialised tasks, such as reviewing articles at others' request, watching current edits for vandalism, watching newly created articles for quality control purposes, or similar roles. Editors who believe they can serve the community better by taking on additional administrative responsibility may ask their peers for agreement to undertake such responsibilities. This structure enforces meritocracy and communal standards of editorship and conduct. At present a minimum approval of 75–80% from the community is required to take on these additional tools and responsibilities. This standard tends to ensure a high level of experience, trust, and familiarity across a broad front of aspects within.
A variety of software-assisted systems and automated programs help editors and administrators to watch for problematic edits and editors. Theoretically all editors and users are treated equally with no "power structure". There is, however, a hierarchy of permissions and positions, some of which are listed hereafter:
has a rich set of methods to handle most abuses that commonly arise. These methods are well-tested and should be relied upon.
As well as systems to catch and control substandard and vandalistic edits, also has a full style and content manual and a variety of positive systems for continual article review and improvement. Examples of the processes include peer review, good article assessment, and the featured article process, a rigorous review of articles that are intended to meet the highest standards and showcase's capability to produce high-quality work.
In addition, specific types of article or fields often have their own specialized and comprehensive projects, assessment processes (such as biographical article assessment), and expert reviewers within specific subjects. Nominated articles are also frequently the subject of specific focus on the neutral point of view noticeboard or in WikiProject Cleanup.
uses MediaWiki software, the open-source program used not only on Wikimedia projects but also on many other third-party websites. The hardware supporting the Wikimedia projects is based on several hundred servers in various hosting centers around the world. Full descriptions of these servers and their roles are available on this Meta-Wiki page. For technical information about, check Technical FAQ. publishes various types of metadata; and, across its pages, are many thousands of microformats.
is run as a communal effort. It is a community project whose result is an encyclopedia. Feedback about content should, in the first instance, be raised on the discussion pages of those articles. Be bold and edit the pages to add information or correct mistakes.
The Help:Contents may be accessed by clicking help displayed under the ► Interaction tab at the top left of all pages.
There is an established escalation-and-dispute process within, as well as pages designed for questions, feedback, suggestions, and comments. For a full listing of the services and assistance that can be requested on, see Wikipedia:Request directory.
Facilities to help users researching specific topics can be found at:
Because of the nature of, it is encouraged that people looking for information should try to find it themselves in the first instance. If, however, information is found to be missing from, be bold and add it so others can gain.
For a listing of ongoing discussions and current requests, see the dashboard. For specific discussion not related to article content or editor conduct, see the Village pump, which covers such subjects as milestone announcements, policy and technical discussion, and information on other specialized portals such as the help, reference and peer review desks. The Community portal is a centralized place to find things to do, collaborations, and general editing help information, and find out what is happening. The Signpost, a community-edited newspaper, has recent news regarding, its sister projects, and the Wikimedia Foundation.
To contact individual contributors, leave a message on their talk page. Standard places to ask policy and project-related questions are the Village pump, online, and the mailing lists, over e-mail. Reach other Wikipedians via IRC and e-mail.
In addition, the Wikimedia Foundation Meta-Wiki is a site for coordinating the various projects and sister projects (and abstract discussions of policy and direction). Also available are places for submitting bug reports and feature requests.
For a full list of contact options, see Wikipedia:Questions.
|Jimmy Wales: The birth of, 2005 TED (conference), 20 mins.|