The 1st Special Forces Operational Detachment-Delta (1st SFOD-D), popularly known as Delta Force, is a U.S. Army unit used for hostage rescue and counterterrorism, as well as direct action and reconnaissance against high-value targets. Delta Force and its Navy counterpart, the United States Naval Special Warfare Development Group (or DEVGRU), often referred to as SEAL Team Six, are the United States military's primary counter-terrorism units and fall under the operational control of the Joint Special Operations Command.