Noncommisioned officers

A non-commissioned officer (sometimes noncommissioned officer), also known as an NCO or Noncom, (US) is an enlisted member of an armed force who has been given authority by a commissioned officer. "Noncom" is the lesser-used term in many militaries since it may also refer to non-combatants. In the USA, the NCO corps includes all the grades of sergeant and, in some militaries, corporals and warrant officers. The naval equivalent includes some or all grades of petty officer, although not all navies class their petty officers as NCOs.

Function
The non-commissioned officer (NCO) corps (which in the USA, includes Navy and Coast Guard petty officers (PO)), is often referred to as "the backbone" of the armed services. NCOs are the primary and most visible leaders for the bulk of Service personnel – the enlisted corps. Additionally, NCOs are the primary military leaders responsible for executing the 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. Another critical role NCOs play is providing advice and guidance to the officer corps. This role is particularly important for junior officers, who begin their careers in a position of authority but lack practical experience, including commanders at all levels and flag officers (generals and admirals). Senior NCOs and Chief Petty Officers, with their wealth of leadership and mission training and experience are the primary link between the bulk of the enlisted personnel and the officers in any military organization.