Wikipedia is a free online encyclopedia launched in 2001, designed for collaborative editing by users from around the globe. Operated by the Wikimedia Foundation, this nonprofit organization provides a platform where anyone can contribute knowledge by creating and editing articles, which collectively encompass over 53 million entries in more than 285 languages. Wikipedia encourages active participation, allowing users to enhance content related to their interests.

Besides the main encyclopedia, Wikimedia Foundation oversees numerous sister projects including Wikiquote, Wiktionary, and Wikinews, each offering a distinct repository of freely accessible information. Users can also find structured educational resources via Wikiversity and explore diverse topics through Wikimedia Commons. This broad array of services underscores Wikipedia's mission to democratize knowledge and enhance information sharing while ensuring that all content remains free under Creative Commons licenses. Wikipedia continues to thrive with hundreds of thousands of daily edits and a robust community of contributors dedicated to maintaining its vast resource of information.