Definition - What does Wikipedia mean?
Wikipedia is a free online encyclopedia that provides open content to its users. It is written collaboratively and openly by a community of both actual and self-proclaimed experts who call themselves Wikipedians. It was created Jimmy Wales and Larry Sanger and was initially slated to be a for-profit website used to support Wales' and Sanger's earlier venture into online encyclopedia space, Nupedia. It is a type of website designed to make collaboration and modification of both content and structure easy, called a "wiki." Its purpose and scope eventually became a website that stores information on nearly all topics known to man, as in an encyclopedia, and thus it was named Wikipedia as an amalgamation of these two concepts.
Techopedia explains Wikipedia
Wikipedia was founded by Jimmy Wales and Larry Sanger on January 15, 2001 and is supported by the Wikimedia Foundation, a nonprofit parent organization. Wikipedia started as a complementary project for an earlier encyclopedia project called Nupedia, which has been defunct since September 26, 2003. It came about because of the stringent review process of Nupedia experts that drove away contributors and stifled its growth. Wales wanted to create another wiki that could foster open collaboration without the fear of humiliation for contributors with articles that they could eventually properly review and then move to Nupedia proper. But the concept grew and quickly overtook the number of articles in Nupedia – Wikipedia had 13,000 articles as of September 25, 2001 as opposed to Nupedia's measly 21 approved articles in its first year. All articles from Nupedia were absorbed into Wikipedia after its demise in 2003.
Articles posted and written for Wikipedia were covered under the GNU Free Documentation License (GFDL) during its initial release, but the Creative Commons License was released in 2002 and it gained ground with bloggers and others who were distributing content over the Web. Since GFDL and the Creative Commons License are incompatible, the Free Software Foundation (FSF) released a new version of the GFDL to suit Wikipedia and relicense its content to be under the Creative Commons Attribution-ShareAlike (CC BY-SA). By law the contributions are still owned by their writers and are allowed to use their articles in any way. However, articles with multiple authors would require permission from all contributors.
Wikipedia also has sister projects which include Wikibooks, Wiktionary, Wikiquote, Wikiversity, Meta-Wiki, Wikispecies and Wikisource. The site is run by the principles articulated by Jimmy Wales, which dictates an adherence to a neutral point of view.