Noncomissioned officer

Common military ranks in English
Navies	Armies	Air forces
Commissioned and Non-commissioned officers
Admiral of the fleet	General of the Army 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 or Trooper	Aircraftman
·

A non-commissioned officer or noncommissioned officer (NCO, colloquially non-com or noncom) is a military officer who has not earned a commission. Such is also called sub-officer in some countries. Non-commissioned officers, in the English-speaking world, usually obtain their position of authority by promotion through the enlisted ranks. In contrast, commissioned officers hold higher ranks than NCOs, have more legal responsibilities, are paid more, and often have more non-military training such as a university diploma. Commissioned officers usually earn their commissions without having risen through the enlisted ranks. "Mustang" is a slang term in the United States Armed Forces used to refer to a commissioned officer who began his or her career as an enlisted service member.

The NCO corps usually includes all grades of corporal and sergeant; in some countries, warrant officers also carry out the duties of NCOs. The naval equivalent includes some or all grades of petty officer, although not all navies class their petty officers as NCOs. There are different classes of non-commissioned officer, including junior non-commissioned officers (JNCO) and senior (or staff) non-commissioned officers (SNCO).

The non-commissioned officer corps is often referred to as "the backbone" of the armed services, as they are the primary and most visible leaders for most military personnel. Additionally, they are the leaders primarily responsible for executing a military organization's mission and for training military personnel so they are prepared to execute their missions. NCO training and education typically includes leadership and management as well as service-specific and combat training.

Senior NCOs are considered the primary link between enlisted personnel and the commissioned officers in a military organization. Their advice and guidance is particularly important for junior officers and in many cases to officers of all senior ranks, who begin their careers in a position of authority without practical knowledge and experience.

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Wikipedia