Wikipedia is a Web-based, free-content online encyclopedia.Since its creation in 2001, Wikipedia has grown rapidly into one of the largest reference web sites, attracting at least 68 millionvisitors yearly by 2008.Wikipedia's intent is to have articles that cover existing knowledge, not create new knowledge (original research). This means that people of all ages and cultural and social backgrounds can write Wikipedia articles. Most of the articles can be edited by anyone with access to the Internet, simply by clicking the edit this page link. Anyone is welcome to add information, cross-references. It consists of more than 10,000,000 articles in more than 260 languages.