Wikipedia is a free online encyclopedia created and edited by volunteers around the world and hosted by the nonprofit Wikimedia Foundation. It provides open access to knowledge across a broad range of subjects, with millions of articles available in English and many other languages. Readers can search and explore content through editions maintained by communities of contributors worldwide, making Wikipedia a multilingual resource for general information and learning.

The Wikimedia Foundation supports Wikipedia and other free knowledge projects, working to keep the encyclopedia available without advertising or a paywall. The site invites readers to contribute financially so it can meet the costs of operating and maintaining the service while preserving its independence and free access. Wikipedia is presented as a human-created resource intended to serve everyone, though its volunteer editing model means it is not described as perfect. Its central offering is a freely accessible collection of articles, supported by a global community and the nonprofit organization that hosts it.