A governor is, in most cases, a public official with the power to govern the executive branch of a non-sovereign or sub-national level of government, ranking under the head of state. In federations, governor may be the title of the politician who governs a constituent state and may be either appointed or elected. The power of the individual governor can vary dramatically between political systems, with some governors having only nominal, largely ceremonial power, while others have complete power over the entire government.
Historically, the title can also apply to executive officials acting as representatives of a chartered company which has been granted exercise of sovereignty in a colonial area, such as the British East India Company or the Dutch East India Company. These companies operate as a major state within a state with its own armed forces.
There can also be non-political governors: high-ranking officials in private or similar governance such as commercial and non-profit management, styled governor(s), who simply govern an institution, such as a corporation or a bank. For example, in the United Kingdom and other Commonwealth countries there are prison governors ("wardens" in the United States), school governors and bank governors.
The adjective pertaining to a governor is gubernatorial, from the Latin root gubernare. The historical female form is governess, though female officials are referred to by the gender-neutral form governor (without the gender specific suffix) of the noun to avoid confusion with other meanings of the term.