An officer is a person who holds a particular office, or position of responsibility within a given organization.
Organizations are typically run using some form of parliamentary/committee system, where members are appointed to serve on committees with responsibility over a particular area of concern for the organization. For example, a social organization may have a Fundraising Committee, a Planning Committee, et cetera. The officers of the organization are typically elected by the members and serve to coordinate the efforts of the various committees as well as provide leadership for the organization as a whole. A common officer structure consists of a President, one or more Vice Presidents, a Secretary, a Treasurer, and other officers as the organizational needs may require.
In government, the term 'officer' is used for a variety of positions. Technically any elected or appointed position in a local, state, or national government can be considered an officer. This is in contrast to civil service positions which are merit-based and not usually considered to be officers, such as GS-level employees of the Federal Government or workers in a state Department of Motor Vehicles. Police and Fire officers are appointed by state and local governments, usually after completing some form of training academy.
In a military system, there are three designations of officer, all denoting positions of responsibility.
- Commissioned Officer - a commissioned officer is appointed to his or her position by the leadership of his or her nation. In the U.S., officers are appointed by the President of the United States. In the United Kingdom, officers are appointed by the authority of the Queen (King). Commissioned officers are the leaders of a military and are trained in areas of leadership, management, as well as their particular military occupation. Commissioned Officers in the U.S. usually earn their commissions by attending one of the service academies, attending ROTC at a non-military university, or persons who already have a college degree may attend Officer Candidate School and earn a Direct Commission. Technically, the President of the United States has the authority to appoint any person he or she chooses to any officer position in the U.S. military. The same is true of the British Monarch for the British military. Commissioned officers must be rendered a salute by junior ranking officers, warrant officer, non-commissioned officers, and enlisted personnel, as well as being addressed as "Sir" or "Ma'am". An interesting distinction is that officers of the U.S. military swear their oaths of office to the U.S. Constitution whereas officers in the British military swear their oaths of office directly to the reigning monarch. American officers never swear allegiance to a particular head of state. The President of the United States, while constitutionally designated as the Commander in Chief of the Armed Forces, is by tradition and statute considered to be a civilian and not a commissioned officer.
- Warrant Officer - In the U.S. military, Warrant Officers start as senior enlisted personnel who earn an expertise in a particular field (helicopter pilots and information technology experts being the most common). They are appointed to Warrant Officer status, which is senior to all enlisted personnel but junior to all commissioned officers. They are saluted by junior personnel and titled "Sir" or "Ma'am" by junior personnel just as commissioned officers are.
- Non-commissioned Officer - A non-commissioned officer (NCO) in the U.S. military is an enlisted person between the grades of E-5 through E-9 (Sergeant through Command Sergeant Major in the Army). They are leaders with a greater focus on occupation specialty than commissioned officers, and serve as advisors to senior military leadership. In particular, the Command Sergeant Major of the Army, the Chief Master Sergeant of the Air Force, the Command Sergeant Major of the Marine Corps, and the Master Chief Petty Officer of the Navy have the unique position of being the senior spokesperson for enlisted persons in their particular branch of the military.