Encyclopedias are designed to introduce readers to a topic, not to be the final point of reference. Wikipedia, like other encyclopedias, is a tertiary source and provides overviews of a topic.
Indeed, the purpose of an encyclopedia is to collect knowledge disseminated around the globe; to set forth its general system to the men with whom we live, and transmit it to those who will come after us, so that the work of preceding centuries will not become useless to the centuries to come; and so that our offspring, becoming better instructed, will at the same time become more virtuous and happy, and that we should not die without having rendered a service to the human race.
Our goal with Wikipedia is to create a free encyclopedia; indeed, the largest encyclopedia in history, both in terms of breadth and in terms of depth. We also want Wikipedia to be a reliable resource.
Wikipedia is first and foremost an effort to create and distribute a free encyclopedia of the highest possible quality to every single person on the planet in their own language.
The mission of the Wikimedia Foundation is to empower and engage people around the world to collect and develop educational content under a free license or in the public domain, and to disseminate it effectively and globally.
A general-purpose encyclopedia is a collection of synthesized knowledge presented from a neutral point of view. To whatever extent possible, encyclopedic writing should steer clear of taking any particular stance other than the stance of the neutral point of view.
Wikipedia's volunteer editors make reference to reliable publications that support what Wikipedia contains, so readers can verify the facts at source. For content to remain on Wikipedia, it must be written from a neutral point of view and attributed to sources that are reliable.
Administration – discusses both the human administrative structure of Wikipedia, as well as its non-human components.
Articles are more important than policy – while familiarizing yourself with how things work on Wikipedia is good, what's even more important is writing good articles
The Free Encyclopedia – describes how Wikipedia is "Free" as in Free Software and Free Culture.
The essence of Wikipedia – describes how Wikipedia uses collective intelligence, collaboration, and preservation to build, expand, and improve content.
Statement of principles – by the co-founder of Wikipedia, Jimmy Wales, as updated by the community since then.
What Wikipedia is not – describes how there are certain things that Wikipedia is not.
Offline access – describes how to access Wikipedia's free content without internet access.
^Diderot, Denis (1755). Encyclopédie. Vol. 5. Translated by Philip Stewart. Paris. p. 635. University of Michigan Library: Scholarly Publishing Office and DLXS. Retrieved on: November 17, 2007
Jimmy Wales: The birth of Wikipedia, 2005 TED (conference), 20 mins.
