Wikipedia is a free, multilingual online encyclopedia that invites anyone to read and edit its articles. Its English edition contains more than seven million articles, covering subjects ranging from current events and history to music, science, and the arts. Volunteer editors create and maintain the content, while community spaces such as the Village Pump, Teahouse, Help Desk, and Reference Desk support discussion, learning, and research. Readers can explore featured articles, daily news, historical anniversaries, and featured pictures, or search the encyclopedia for information on particular topics.

Wikipedia is part of a broader family of volunteer projects hosted by the Wikimedia Foundation, a nonprofit organization. These offerings include Wikimedia Commons, a free media repository; Wikidata, a knowledge base; Wikibooks, a source of free textbooks and manuals; Wikisource, a free-content library; and Wiktionary, a dictionary and thesaurus. Other projects provide quotations, species information, travel guides, learning resources, and software development tools. Together, Wikipedia and its sister projects make accessible reference and educational resources available to people around the world.