President is a position held by many leaders of organizations, companies, trade unions, universities, and countries. Currently most companies use the term CEO (Chief Executive Official) instead of President for the heads of their companies. Originally, the term referred to the presiding officer of a ceremony or meeting (i.e. chairman); but today it most commonly refers to an official with executive powers.
Among other things, president today is a common title for the head of state of most republics, whether popularly elected, chosen by the legislature, or a special electoral college. The title of president is often adopted by dictators as well, such as Fidel Castro.