When the Website Wikipedia.org first went online January 15th 2001 which was 18 years ago as of this year the first page on Wikipedia was the page describing Wikipedia.org.
Here's the link to the page about Wikipedia
https://en.wikipedia.org/wiki/Wikipedia
Wikipedia.org was created by Jimmy Wales and Larry Sanger and has grown to be a large website which is in the top visited websites in the world with billions of monthly visitors.
Wikipedia.org can be accurate and inaccurate at the same time on different articles since anybody can edit the Wikipedia.org articles that are not protected.