An enlisted rank in the Military of the United States is generally any rating below that of a commissioned officer. The term can be inclusive of non-commissioned officers and warrant officers. In its most exclusive sense, the term applies only to the lowest ranks of military service. Though it is the lowest of the ranks, it is the most important. The lower-enlisted (in the United States Army, E-4 and below) are the core of the working force, while the NCO corps (in the United States Army, E-5 and above) provides the direct leadership and training to these soldiers.