Which of the following is considered an external network?

An external network refers to groups, organizations, or entities that operate outside a specified system or organization. In this context, the USAR (United States Army Reserve) units are classified as an external network because they function independently from the Active Army components and their structures, such as USAREC units and internal Army institutions.

These external networks are crucial for collaboration and support, allowing the Army to integrate resources and personnel from different branches and components. The presence of USAR units signifies a broader scope of military readiness and operational capability beyond the immediate active-duty environment. This distinction is essential for understanding how various units interact and support the mission of the Army as a whole.

In contrast, the other options—USAREC units, internal Army institutions, and military personnel—are all part of the internal structure of the Army and do not fit the definition of an external network as they operate within the existing organizational framework.