"Division or Group Supervisors report to the Operations Section Chief (OSC) (or Operations Branch Director when activated). Supervisors are responsible for the implementation of their assigned portion of the Incident Action Plan (IAP). They are also responsible for the assignment of resources within their Division or Group, reporting on the progress of control operations, and the status of resources within their Division or Group. Division Supervisors are assigned to a specific geographical area of an incident. Group Supervisors are assigned to accomplish specific functions within the incident (i.e., Hazardous Material, Medical)."
Coffee Break Training - Command and Control Series No. CC-2013-9
United States Fire Administration: http://www.usfa.fema.gov/