The Defense Language Institute (DLI) is a United States Department of Defense (DoD) educational and research institution, which provides linguistic and cultural instruction to the Department of Defense, other Federal Agencies and numerous customers around the world. The Defense Language Institute is responsible for the Defense Language Program, and the bulk of the Defense Language Institute's activities involve educating DoD members in assigned languages, and international personnel in English. Other functions include planning, curriculum development, and research in second-language acquisition.