ENLISTED SOLDIER OR OFFICER

Enlisted Soldiers are the backbone of the U.S. Army. Much like employees at a company, every enlisted Soldier
has a trained speciality, and plays a part in the success of his or her unit. Ranks for enlisted Soldiers range from Private to Sergeant Major of the Army. Warrant Officers are specialized experts and trainers. They make up the technical foundation of the U.S. Army. Unlike commissioned Officers, who focus more on commanding troops and staff duty positions, Warrant Officers are focused solely on advancing within their chosen career specialites.
Commissioned Officers are the managers and planners of the Army. They are generally tasked with leading Soldiers. One of the best ways for your son or daughter to become an Army Officer is to join Army ROTC as a college student.

 http://www.goarmy.com/parents/what-to-expect/service-options.html