A Non-Commissioned Officer is a military rank referring to an officer who has not been promoted to hold high office. NCOs are still leaders, though, the primary ones for most military personnel. They are responsible for executing missions and for providing adequate and specialized training to their subordinates.
NCOs command privates, corporals, and sergeants rank under them. They are trained for combat as well as management and function as a link between enlisted soldiers and commissioned officers. They provide guidance and advice, first and foremost, to junior officers.
The duties of NCOs are varied, and the perks are many. Although they only make 11% more than the average national salary, with a median annual income of around $45,978, they get schooling and training opportunities, with a chance to earn bonuses as well.