Some presidential boards, committees, and commissions function organizationally as subunits of the White House Office.

[4] Although still a subunit of the EOP, the White House Office remains the center of the presidential staff system.

In many ways it is closest to the president both in physical proximity, its top aides occupy most of the offices in the West Wing, and in its impact on the day-to-day operations, deliberations, policy agendas, and public communications of a presidency.

[1] The issues that confront the United States at any one time cannot be dealt with by the president alone, and therefore the president draws on the expertise of others in the administration and even within an administration as one chief of staff may differ from a predecessor or successor.

At least in theory, they are the coordinators bringing the pieces together; they are the tone-setters and disciplinarians making for good organizational order, and often act as the gatekeeper for the president, overseeing every person, document and communication that goes to the president.