Ministry or department (also less commonly used secretariat, office, or directorate) are designations used by first-level executive bodies in the machinery of governments that manage a specific sector of public administration.
[1] These types of organizations are usually led by a politician who is a member of a cabinet—a body of high-ranking government officials—who may use a title such as minister, secretary, or commissioner, and are typically staffed with members of a non-political civil service, who manage its operations; they may also oversee other government agencies and organizations as part of a political portfolio.
The federal Government of Canada uses the term department to refer to its first-level executive bodies.
Despite the difference in nomenclature, both the provincial and federal governments use the term "minister" to describe the head of a ministry or department.
[4] Some countries, such as Switzerland, the Philippines and the United States, do not use or no longer use the term "ministry" and instead call their main government bodies "departments".
However, in other countries such as Luxembourg a department is a subdivision of a ministry, usually led by a government member called a secretary of state who is subordinate to the minister.
Although the term "ministry" has been eliminated from the Government communication and from most of the new published laws, it continues to be used in some legislation, especially those referring to some government areas that existed for a long time as ministries (Finance, National Defense, Foreign Affairs, Health, etc.).
In Nigeria each ministry is led by a minister who is not a member of the Nigerian legislature (due to the separation of powers) and is responsible to the popularly elected president.