the active and reserve component forces of the United States Army, Marine Corps, Navy and Air Force within the US military, as designated by the Secretary of Defense and specifically organized, trained, and equipped to conduct and support special operations.
In the People's Republic of China, the special operations forces of the People's Liberation Army are units that conduct direct action and reconnaissance, including in enemy rear areas, to prepare the advance of friendly forces; they also perform counter-terrorism operations, although that mission is formally assigned to People's Armed Police.