An example of Wikipedia is a web-based encyclopedia to which users can contribute.
Wikipedia - Computer Definition
The world's largest encyclopedia available on the Web at www.wikipedia.com. Wikipedia is user generated, and anyone can create or edit an article (see wiki). Founded in 2001 by Jimmy Wales, as of 2015, there were more than 25 million articles in more than 250 languages on every conceivable subject on the planet. Wikipedia has been written and edited by millions of contributors, some 70,000 of which are active at any given time. Admired and Criticized Wikipedia's range of subjects is unparalleled, covering topics that would never appear in any conventional encyclopedia, online or print. There are so many "eyes" looking at an entry that erroneous information is often caught rather quickly. However, Wikipedia is also disparaged because people can make edits without divulging their credentials or experience in the subject. In addition, if vendors see comments about their products, nothing stops them from editing the article in their favor. There Is a Hierarchy Although anybody can edit an article, there is a hierarchy. Several hundred Wikipedia administrators have the power to delete entries and block IP addresses to keep people from adding obscene language or stating extremely strong opinions. Jimmy Wales has the ultimate authority. See Wikipedian, Wikia and Uncyclopedia..