Chain of command is an orderly line that details how authority flows through the hierarchy of the incident management organization. Chain of command:

• Allows an Incident Commander to direct and control the actions of all personnel on the incident. 
• Avoids confusion by requiring that orders flow from supervisors.

Chain of command does NOT prevent personnel from directly communicating with each other to ask for or share information. While formal direction and control follows the chain of command, informal information sharing occurs throughout the ICS structure.