Harvard University Libraries is one of the largest academic library systems in the world, consisting of over 70 individual libraries. It holds more than 18 million items, including books, manuscripts, and digital resources, serving the research needs of Harvard's students and faculty. The library system includes notable libraries such as the Widener Library, which is the main library, and the Houghton Library, known for its rare books and manuscripts. Harvard University Libraries supports a wide range of disciplines and provides access to extensive collections, making it a vital resource for scholars and researchers.