In relation to a company or other formal organization, a director is an officer (that is, someone who works for the company) charged with the conduct and management of its affairs. A director may be an inside director (a director who is also an officer or promoter or both) or an outside, or independent, director. The directors collectively are referred to as a board of directors. Sometimes the board will appoint one of its members to be the chair or chairperson of the board of directors, traditionally also called chairman or chairwoman.

Theoretically, the control of a company is divided between two bodies: the board of directors, and the shareholders in general meeting. In practice, the amount of power exercised by the board varies with the type of company. In small private companies, the directors and the shareholders will normally be the same people, and thus there is no real division of power. In large public companies, the board tends to exercise more of a supervisory role, and individual responsibility and management tends to be delegated downward to individual professional executive directors (such as a finance director or a marketing director) who deal with particular areas of the company's affairs.

Another feature of boards of directors in large public companies is that the board tends to have more de facto power. Between the practice of institutional shareholders (such as pension funds and banks) granting proxies to the board to vote their shares at general meetings and the large numbers of shareholders involved, the board can comprise a voting bloc that is difficult to overcome. However, there have been moves recently to try to increase shareholder activism amongst both institutional investors and individuals with small shareholdings. A board-only organization is one whose board is self-appointed, rather than being accountable to a base of members through elections; or in which the powers of the membership are extremely limited.