Wikipedia is a multi language, free content encyclopedia based on open and editable content model. It is the largest and most popular general reference on the Internet, [3] [4] [5], known as one of the most popular websites. It is owned and supported by Wikimedia Foundation, a non-profit organization that operates with any funds it receives from its annual fundraising pool.

Wikipedia was launched by Jimmy Wales and Larry Sanger on January 15, 2001. Sanger created its name, Wikipedia and the abbreviation of encyclopedia. At first, there was only English version, but similar versions in other languages developed rapidly, with different contents and editing methods. English Wikipedia has 5647253 articles, the largest of more than 290 Wikipedia. Overall, as of February 2014, Wikipedia had 40 million articles in 301 different languages, 18 billion page views and nearly 500 million monthly independent visitors.

As of March 2017, Wikipedia has about 40000 selected articles and excellent articles covering important topics. In 2005, nature published a peer review, comparing 42 scientific articles from Encyclopedia Britannica and Wikipedia, and found that the accuracy level of Wikipedia is close to that of Encyclopedia Britannica. Time magazine points out that the open policy of allowing anyone to edit makes wikipedia the largest and possibly the best encyclopedia in the world, which proves Jimmy Wales' vision.

Wikipedia has been criticized for showing systematic bias, showing a mixture of "truth, semi truth and some false statements", and has been manipulated and controversial. In 2017, Facebook announced that it would help readers find fake news through appropriate links to Wikipedia articles. YouTube announced a similar plan in 2018. To this end, the Washington Post is entitled "Wikipedia, the 'good cop' of the Internet.".