Officer (armed forces)

Common military ranks in English
Navies	Armies	Air forces
Commissioned and Non-commissioned officers
Admiral of the fleet	Marshal or Field marshal	Marshal of the air force
Admiral	General	Air chief marshal
Vice admiral	Lieutenant general	Air marshal
Rear admiral	Major general	Air vice-marshal
Commodore	Brigadier or Brigadier general	Air commodore
Captain	Colonel	Group captain
Commander	Lieutenant colonel	Wing commander
Lieutenant commander	Major or Commandant	Squadron leader
Lieutenant	Captain	Flight lieutenant
Sub-lieutenant	Lieutenant or First lieutenant	Flying officer
Ensign	Second lieutenant	Pilot officer
Midshipman	Officer cadet	Flight cadet
Enlisted grades
Warrant officer or Chief petty officer	Warrant officer or Sergeant major	Warrant officer
Petty officer	Sergeant	Sergeant
Leading seaman	Corporal	Corporal
Seaman	Private	Aircraftman

An officer is a member of an armed force or uniformed service who holds a position of authority. Used without further detail, the term "officer" almost always refers to commissioned officers, the most senior portion of a force who derive authority from a commission, usually from a state. In its broadest sense, the term "officer" also includes warrant officers and lower level leaders who are referred to as non-commissioned officers.

The proportion of officers varies greatly. Officers typically make up between an eighth and a fifth of modern armed forces personnel. In 2013, officers were the senior 17% of the British armed forces, and the senior 13.7% of the French armed forces. In 2012, officers made up about 18% of the German armed forces, and about 17.2% of the United States armed forces.

Historically, however, armed forces have generally had much lower proportions of officers. During the First World War, fewer than 5% of British soldiers were officers (partly because World War One junior officers suffered very high casualty rates). In the early twentieth century, the Spanish army had the highest proportion of officers of any European army, at 12.5%.

Within a nation's armed forces, armies (which are larger) tend to have a lower proportion of officers, but a higher total number of officers, while navies and air forces have higher proportions of officers. For example, 13.9% of British army personnel and 22.2% of the RAF personnel were officers in 2013, but the army had a larger total number of officers.

Having officers is one requirement for combatant status under the laws of war, though these officers need not have obtained an official commission or warrant. In such case, those persons holding offices of responsibility within the organization are deemed to be the officers, and the presence of these officers connotes a level of organization sufficient to designate a group as being combatant.

Commissioned officers are typically the only persons, in an armed forces environment, able to act as the commanding officer (according to the most technical definition of the word) of a military unit. A superior officer is an officer with a higher rank than another officer, who is a subordinate officer relative to the superior.

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Wikipedia