The Library of Congress is the national library of the United States and the largest library in the world by number of items catalogued. It is the research arm of the U.S. Congress and serves as the national library of the United States. The Library of Congress is located in three buildings in Washington, D.C., and includes the main library building, the Thomas Jefferson Building, as well as the John Adams Building and the James Madison Memorial Building. The Library of Congress holds more than 162 million items in various languages, disciplines, and formats, including books, manuscripts, maps, photographs, films, and sound recordings. It also has a large collection of digital materials, including electronic books, websites, and digitized collections. The Library of Congress serves as a resource for Congress and the American people, and its collections are open to the public for research and study.