Cambridge University Library, referred to within the University as "the University Library" or just "the UL", is the central research library. It holds around 8 million items (including maps and sheet music) and, in contrast with the Bodleian or the British Library, many of its books are available on open shelves. It is one of the six legal deposit libraries in the United Kingdom, and is therefore entitled to request a free copy of every book published in the UK and Ireland. Through legal deposit, purchases and donations it receives around 100,000 books every year.
There are twenty-one affiliate libraries associated with the main University Library, for the purpose of central governance and administration. The affiliated libraries are a growing network, with a remit to "maximise efficiency while catering to the diverse range of user needs."
There is at least one library in every college within the University. All Colleges have a working library, generally to support undergraduate teaching. Material in the College libraries will typically cover all Tripos subjects. Many of the Colleges also have special collections such as early printed books and manuscripts, and are often kept in a separate library. For example, Trinity College's Wren Library holds more than 200,000 books printed before 1800, while the Parker Library at Corpus Christi College, has one of the greatest early medieval European manuscript collections in the world, with over 600 manuscripts.