That depends on the department. If the department is a Cabinet Level department (Defense, Interior, etc.) the head is a cabinet secretary, while other departments (Postal Service, Fish and Wildlife Department) are not Cabinet Level and therefore their heads are not cabinet secretaries.
The newest Cabinet department is the Department of Homeland Security, created in 2003 in response to the attacks of September 11, 2001.
The Department of Homeland Security was a new department created in 2003.
United States Department of Homeland Security
HHS
The department of transportation
FEMA now is a part of the Department of Homeland Security.
The US government has a cabinet-level Department of Transportation. However, most states also have their own Departments of Transportation.
There are fifteen cabinet level departments in the executive branch of the U.S. federal government. Four were created by George Washington during his presidency: the State Department, the Treasury Department, the Justice Department, and the War Department, which became the Defence Department in 1946.
Department of Justice- Attorney General
The US cabinet agency that enforces the laws of the federal government is the Department of Justice (DOJ). The agency is responsible safety of the public from foreign and domestic threats.
foreign relations