Ranking in the United States Army follows a system of grading its officers in categories of seniority and command. Ranks are segregated into "Officers" and "Non-Commissioned Officers".
Commissioned Officers include Flag Officers (Generals who command brigades and larger), Field Grade Officers (commanding battalions and regiments), Company Grade or Junior Officers (Captains and lower rank Officers leading smaller units) and Warrant Officers (possessing technical or other specialized skills who do not serve in a leadership or command capacity.
Ranks for Non-Commissioned Officers consist of enlisted personnel performing administrative duties. This rank is positioned below Junior Commissioned Officers, in spite of the fact that the required responsibilities are generally more complex and in depth than those of the Junior Commissioned Officers. Included here are Sergeants, Privates, Specialists, Staff Officers and others. Often the personnel in these ranks handle planning, training, logistics, supply, pay and many other duties of this nature.
Commissioned Officers are actively recruited from the following locations: US Military Academies, enlisted soldiers or graduates from Officer Candidate School, Army Reserve Officer Training Corps graduates, direct commission of lawyers, doctors, nurses and veterinarians, and battlefield commissions for valor and leadership.