Wikipedia is a multilingual, Web-based, free-content encyclopedia project. The name "Wikipedia" is a portmanteau (a combination of portions of two words and their meanings) of the words wiki (a type of collaborative Web site) and encyclopedia. Wikipedia's articles provide links to guide the user to related pages with additional information.
Wikipedia is written collaboratively by volunteers from all around the world; anyone can edit it. Since its creation in 2001, Wikipedia has grown rapidly into one of the largest reference Web sites, attracting at least 684 million visitors yearly by 2008.