what is the difference between an officer and a non commissioned member
Non-commissioned officer A non-commissioned officer or noncommissioned officer (NCO, colloquially non-com or noncom) is a military officer who has not earned a commission.[1][2][3] 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.[4] 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.[citation needed]
Staff sergeant Staff sergeant (SSG) is E-6 rank in the U.S. Army, just above sergeant and below sergeant first class, and is a non-commissioned officer. Staff sergeants are generally placed in charge of squads, but can also act as platoon sergeants in the absence of a sergeant first class. In support units, staff sergeants ordinarily hold headquarters positions because of the number of slots available for them in these units. Staff sergeants are typically assigned as a squad leader or company operations non-commissioned officer in charge at the company level, but may also hold other positions depending on the type of unit. Staff sergeants are referred to as "Sergeant" except in certain training environments and schools. The NATO code is OR-6.