Unlike most universities, it does not take students, nor does it award degrees. Rather it runs a number of research centres around the world, where research fellows or PhD students from other universities can come to do research. It especially targets researchers and students from developing countries.
UNU is headed by a Rector, and headquartered in Tokyo, Japan. It does not receive any funding from the regular UN budget; it relies instead upon voluntary contributions from member states and the return on its investments, which are currently valued at USD 350 million. The annual budget of UNU is approximately USD 70 million per annum.
See http://www.unu.edu for more information.