Note: This is the first in a weekly series of explanatory posts on the officials and agencies included in the President’s Cabinet.

When Obamacare was signed into law in 2010, the Catholic nuns didn’t expect it would affect their religious liberty. Nor did they suspect that in a few years the Department of Health and Human Services (HHS) would restrict their freedom of conscience. Yet it was that Cabinet-level government agency that issued a mandate requiring the women to disregard their deeply held convictionsby providing health care coverage for contraceptives and abortifacients. Even though it would have caused no harm to give the nuns an exemption to the mandate, the federal agency refused to back down until forced to do so by the Supreme Court.

The attempted coercion of the Little Sisters of the Poor was a wake-up call for many Christians. The expansive power of government agencies was being used in an unprecedented manner to control and restrict liberties many Americans had taken for granted. And the case raised even greater concerns: If HHS could threaten religious freedom, what could even more powerful federal agencies do?

Unfortunately, many Americans have only a basic understanding of what the President’s Cabinet even is, much less how it can affect our lives. To increase awareness, this weekly series will explain the functions of Cabinet-level departments, consider how they can expand or restrict liberties, and look at the men and women President-elect Trump has nominated to lead these agencies.

But first, here are answers to some basic questions you might have about the Cabinet.

Why is it called a Cabinet?

In 17th century usage, a “cabinet” referred to a “private room where advisors meet.” That led to the modern definition of “a body of persons appointed by a head of state or a prime minister to head the executive departments of the government and to act as official advisers.”

What departments constitute the Cabinet?

The Cabinet includes the Vice President and the heads of 15 executive departments: the Secretaries of Agriculture, Commerce, Defense, Education, Energy, Health and Human Services, Homeland Security, Housing and Urban Development, Interior, Labor, State, Transportation, Treasury, and Veterans Affairs, as well as the Attorney General.

There are also several “Cabinet-level officials” who are not part of the Cabinet: the White House Chief of Staff, the Administrator of the Environmental Protection Agency, the Director of the Office of Management & Budget, the United States Trade Representative (who is given the title of ambassador), the Ambassador for the United States Mission to the United Nations, the Chair of the Council of Economic Advisers, and the Administrator of the Small Business Administration.

Why are the members of the Cabinet called Secretaries?

With some exceptions (e.g., Attorney General), the Cabinet-level departments are referred to as Secretaries. This usage dates back to the 1590s when the original meaning of a “person entrusted with secrets” was applied to “ministers presiding over executive departments of state.”

What law authorizes or requires there to be a Cabinet?

The U.S. Constitution doesn’t require the president to have a formal Cabinet, though the ‘Opinion Clause’ (Article II, Section 2) does outline the role of such a group: “[The President] may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Offices.

Although the Cabinet is not required by law, the general structure has been in place since the presidency of George Washington.

Does Congress have to approve the president’s Cabinet appointments?

The Senate does, through their “advise and consent” role. The Inferior Officers Clause (Article II, Section 2) states that “the Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments.”

While The Supreme Court has never clearly defined what constitutes “Heads of Departments,” the judicial branch has regularly deemed it applicable to Cabinet-level officials.

How much do Cabinet headsget paid?

The pay of Cabinet headsis set by law (5 U.S.C. § 5312) as being Level I of the Executive Schedule, which is currently $203,700 a year. (More than Senators and Congressional Representatives ($174,000) but less than the Vice President ($235,000), House and Senate majority/minority leaders ($193,400), or Speaker of the House ($223,500).)

Why are Cabinet officials in line for the presidency?

If neither the President or the Vice President can “discharge the powers and duties of the office” because of death or incapacitation, then Congress is tasked by the Twentieth Amendment to determine who shall act as President.

In 1947, Congress updated the Presidential Succession Act (3 U.S.C.§19) which clarifies that:

If, by reason of death, resignation, removal from office, inability, or failure to qualify, there is no President pro tempore to act as President under subsection (b) of this section, then the officer of the United States who is highest on the following list, and who is not under disability to discharge the powers and duties of the office of President shall act as President: Secretary of State, Secretary of the Treasury, Secretary of Defense, Attorney General, Secretary of the Interior, Secretary of Agriculture, Secretary of Commerce, Secretary of Labor, Secretary of Health and Human Services, Secretary of Housing and Urban Development, Secretary of Transportation, Secretary of Energy, Secretary of Education, Secretary of Veterans Affairs, Secretary of Homeland Security.

During the Cold War, it became mon practice for the President to choose a designated survivor (or designated successor) during certain events when the President, Vice President, and Cabinet are gathered at a single location, such as during State of the Union addresses and presidential inaugurations. The designated survivor is protected by the Secret Service at an undisclosed and protected location for the entirety of the event.

Previous and ing posts in this series:Secretary of State,Secretary of the Treasury,Secretary of Education, Secretary of Labor,Secretary of Defense, Attorney General,Secretary of the Interior, Secretary of Agriculture, Secretary of Commerce,Secretary of Health and Human Services,Secretary of Housing and Urban Development, Secretary of Transportation, Secretary of Energy,Secretary of Veterans Affairs, Secretary of Homeland Security