Most of this book is aimed at folks who want to edit Wikipedia articles and become more active in the Wikipedia community. But this appendix is all about appreciating Wikipedia as a reader. It gives you some background on what Wikipedia is and how to get the most out of it even if you have no intention of editing an article.
Wikipedia is a collaboratively written encyclopedia. It’s a wiki, which means that the underlying software (in this case, a system called MediaWiki) tracks every change to every page. That change-tracking system makes it easy to remove (revert) inappropriate edits, and to identify repeat offenders who can be blocked from future editing.
Wikipedia is run by the not-for-profit Wikimedia Foundation; that’s why you don’t see advertising on any of its pages, or on any of Wikipedia’s sister projects that the Foundation runs (more on those later). To date, almost all the money to run Wikipedia and its smaller sister projects has come from donations. Once a year or so, for a month or so, you may see a fundraising banner instead of the standard small-print request for donations at the top of each page, but, so far, that’s about as intrusive as the foundation’s fundraising gets.