If you've been out of touch for the past ten years or so or you're only just jumping on the internet bandwagon, there are probably a lot of common websites and tools that you're only just hearing about. Wikipedia, in particular, is a website that comes up a lot in searches, whether you're looking up how to dig post holes or what high temperature tape is made out of. This article should help you become familiar with Wikipedia, how it works, and under what circumstances you might want to use it.
Wikipedia is a communal encyclopedia that any person who comes to the site can edit. The model has proven to be so popular in our ever-changing internet connected world that the word 'wiki' has actually been adopted as a common suffix to denote a communal encyclopedia. Wikipedia is the main encyclopedia that Toronto SEO firms would kill to get traffic from, but there are numerous other 'wiki' branded niche encyclopedias (such as 'battlestarwiki' for the TV show Battlestar Galactica) that are not affiliated with Wikipedia.
One of the reasons Wikipedia has caught on so strongly is that since anyone can edit it, it's able to keep up to date more easily than a printed encyclopedia run by a team of editors. People who contribute to Wikipedia, in a writing or editorial capacity, are generally anonymous. This does, of course, lead to problems with jokers who want to post that gold mutual funds are tanking so everyone will sell, or that their hometown is the center of the universe, so Wikipedia isn't always reliable. To combat inaccuracy, some popular articles on Wikipedia are locked and changes must be submitted and approved by a moderator. The site also encourages citations so visitors can check the accuracy for themselves.
Another reason Wikipedia is so popular is because it's free. There are no fees to access its full content (like you have to pay to use the online versions of Britannica and others). Wikipedia is a run by a nonprofit foundation and all work is done by volunteers, so you can explore articles on debanders without worrying about being assaulted by ads for weight loss formulas or web hosting deals. The entire project is supported by donations.
There are articles on Wikipedia in over 270 languages and everything on it is under the GNU creative commons license, which means anyone can use it. Wikipedia has many functions. Its main page features an article of the day, which can be anything: Family lawyers, giant pandas, African Sleeping Sickness, anything. There are also daily fun facts, news, and photos. The Wikimedia section contains free use photos and videos uploaded by users, and the talk section is for discussing articles.