.edu.edu is the Internet top-level domain for educational institutions.
Created in January 1985 as one of the first top-level domains, .edu was originally intended for educational institutions anywhere in the world. With few exceptions, however, only those in United States registered such domains, while educational institutions in other countries usually used domain names under the appropriate country code TLD. In some countries a second-level domain is used to indicate an educational institutions (e.g .edu.au in Australia, .ac.uk in the United Kingdom), in others only the country code is used (e.g. in Canada and Germany).
Under the present system, only postsecondary institutions that are accredited by an agency on the U.S. Department of Education's list of Nationally Recognized Accrediting Agencies are eligible to apply for a .edu domain. Most of these accrediting agencies accredit only U.S. institutions, so only a small number of non-U.S. institutions qualify, and .edu remains an almost exclusively American top-level domain. The restriction to post-secondary institutions does not apply to the corresponding domains in some other countries; for example the British .ac.uk second-level domain is also used by Further Education colleges.
Note that the current eligibility requirements only apply to new applicants. There are several non-qualifying institutions that have .edu domains obtained before the current rules came into force.