A Chief Operating Officer (COO), also called the chief operations officer, is a position that can be one of the highest-ranking executive positions in an organization, comprising part of the "C-Suite". The COO is responsible for the daily operation of the company, and routinely reports to the highest ranking executive, usually the chief executive officer (CEO). The COO is usually the second in command at the firm, especially if the highest ranking executive is the Chairman and CEO.
Unlike other C-Suite positions, which tend to be defined according to commonly designated responsibilities across most companies, the COO job tends to be defined in relation to the specific CEO with whom he/she works, given the close working relationship of these two individuals. In many ways, the selection of a COO is similar to the selection of a Vice President of the United States: the role (including the power and responsibilities therein) can vary dramatically, depending on the style and needs of the President. Thus, the COO role is highly contingent and situational, as the role changes from company to company and even from CEO to successor CEO within the same company.
In a similar vein to the COO, the title of corporate President as a separate position (as opposed to being combined with a "C-Suite" designation, such as "President and CEO" or "President and COO") is also loosely defined. The President is the legally recognized highest "titled" corporate officer, ranking above the various Vice Presidents (including Senior Vice President and Executive Vice President), however that post on its own is generally considered subordinate to the CEO.
Lloyd E. Reuss was President of General Motors from 1990 to 1992, as the right-hand man of Chairman and CEO Robert C. Stempel. Stempel insisted on naming Reuss as company president in charge of North American operations, the board reluctantly agreed but showed their displeasure by not giving Reuss the title of COO.
Richard D. Parsons was number two in the company hierarchy during his tenure as President of Time Warner from 1995 to 2001, but he had no authority over the operating divisions, and instead took on assignments at the behest of Chairman and CEO Gerald Levin.