Wikipedia is a free online encyclopedia created and edited by volunteers around the world. Hosted by the nonprofit Wikimedia Foundation, it provides open access to articles across a wide range of subjects and is available in many languages, with millions of entries in major editions such as English, German, French, Spanish, Japanese, and Chinese. Readers can search and explore information, contribute to the encyclopedia, and support its work through donations.

Wikipedia is part of a broader collection of free knowledge resources hosted by the Wikimedia Foundation. These include Wikimedia Commons for free media, Wikivoyage travel guides, Wiktionary dictionaries, Wikibooks textbooks, Wikidata’s knowledge base, Wikiversity learning resources, Wikiquote quotations, Wikisource texts, Wikispecies species information, and Wikifunctions. The foundation also supports MediaWiki, free wiki software, and Meta-Wiki, a space for community coordination and documentation. Wikipedia’s official mobile app lets users save articles for offline reading, sync reading lists across devices, and customize their reading experience. Its content is available under a Creative Commons Attribution-ShareAlike License.