The ARRL defines the EC as “…the person responsible for the ARES group at the local level. Working with local community officials, the Section Emergency Coordinator (SEC), and other field appointees, the EC leads his or her local ARES group through the planning, preparedness, and response phases.”
In simple terms, the EC is the coach of a team of talented Hams. He works with them to provide a coordinated response based on training and practice.