Chief Executive Officer (CEO) is the job of having the ultimate executive responsibility or authority within an organization or corporation. Although there may be more than one CEO in a company, generally the job is not shared anymore. It is feared that such an arrangement may create confusion within the organization about who is ultimately in charge. All other management reports to the Executive Officer.
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.
By comparison of CEO with CFO as strategic business partner and statutory duties under SEC and Sarbanes-Oxley Act, both are equal ranking top executive and separate posts. For larger corporations, CEOs and CFOs often hold MBAs or the Juris Doctor degree.