Chief executive officertitle generally given to the highest member of day-to-day management in a corporation who usually has the ultimate executive authority within an organization or company.
The CEO usually reports to, and is a member of, the company's board of directors. The CEO may also be the chairman of the board or the company president in small businesses, but these roles are often separated in larger organizations, to prevent the company from becoming dominated by a single personality, and to prevent a conflict of interest against the owners (the shareholders).
In the United States this is a title used by the highest authority within most businesses, regardless of their actual size. In other English speaking countries (most notably countries in the Commonwealth of Nations) the term is used mainly in publicly traded corporations, and in privately held companies the term Managing Director is much more common.