A number of universities in the United Kingdom are composed of colleges. These can be divided into three broad categories. In the case of the 18 constituent colleges of the federal University of London, the colleges operate largely as self-governing universities, with teaching and research activities and control over their own finances and admissions, and some have their own degree awarding powers. In the case of Durham University, the University of Cambridge and the University of Oxford, the constituent colleges have the legal status of 'listed bodies' and have some academic activities but are primarily centres of student life. In the case of the Plate glass universities: the University of Kent, Lancaster University, and the University of York, colleges have less autonomy operating under a different legal footing, but still perform some independent functions.