The title, chief of staff, identifies the leader of a complex organization, institution, or body of persons and it also may identify a Principal Staff Officer (PSO), who is the coordinator of the supporting staff or a primary aide-de-camp to an important individual, such as a president.

In general, a chief of staff provides a buffer between a chief executive and that executive's direct-reporting team. The chief of staff generally works behind the scenes to solve problems, mediate disputes, and deal with issues before they bubble up to the Chief Executive. Often Chiefs of Staff act as a confidante and advisor to the Chief Executive, acting as a sounding board for ideas. Ultimately the actual duties depend on the actual position and the people involved.

In general, the positions listed below are not "chiefs of staff" as defined at the top of this page. In general, they are the heads of the various forces/commands. Note that, in general, they tend to have subordinates that do fulfill the "chief of staff" roles.

"The Man" is a slang phrase that may refer to the government or to some other authority in a position of power. In addition to this derogatory connotation, it may also serve as a term of respect and praise.

The phrase "the Man is keeping me down" is commonly used to describe oppression. The phrase "stick it to the Man" encourages resistance to authority, and essentially means "fight back" or "resist", either openly or via sabotage.

The earliest recorded use^{[citation needed]} of the term "the Man" in the American sense dates back to a letter written by a young Alexander Hamilton in September 1772, when he was 15. In a letter to his father James Hamilton, published in the Royal Dutch-American Gazette, he described the response of the Dutch governor of St. Croix to a hurricane that raked that island on August 31, 1772. "Our General has issued several very salutary and humane regulations and both in his publick and private measures, has shewn himself the Man." ^{[dubious – discuss]} In the Southern U.S. states, the phrase came to be applied to any man or any group in a position of authority, or to authority in the abstract. From about the 1950s the phrase was also an underworld code word for police, the warden of a prison or other law enforcement or penal authorities.

A press secretary or press officer is a senior advisor who provides advice on how to deal with the news media and, using news management techniques, helps their employer to maintain a positive public image and avoid negative media coverage.

They often, but not always, act as the organization's senior spokesperson. Many governments also have press secretaries. A deputy press secretary is typically a mid-level political staffer who assists the press secretary and communications director with aspects of public outreach. They often write the press releases and media advisories for review by the press secretary and communications director. There are usually assistant press secretaries and press officers that support the press secretary.