Simplify the following text for a Grade 9 native English-speaking person.
Original: The Defense Intelligence Agency , or DIA , is a major producer and manager of military intelligence for the United States Department of Defense , employing over 11,000 military and civilian employees worldwide . The Defense Intelligence Community is headed by the DIA , through its Director ( who chairs the Military Intelligence Board ) , and coordinates the activities of the Army , Navy , Marine Corps , and Air Force intelligence components .
Simplified: DIA also runs the National Defense Intelligence College .