Dave, N9KMY, shared this article by Arc Thames, W4CPD, that discusses the ICS system,

Understanding the National Incident Management System (NIMS) and Incident Command System (ICS) is crucial for volunteers in disaster response and emergency communications. ​ Many agencies require basic training before allowing volunteers to participate. ​ This training helps volunteers understand the ICS organization and work effectively within the established chain of command. ​ The article emphasizes the importance of training and provides a guide to the primary ICS courses required for volunteers. ​

Read the complete article at
https://acrobat.adobe.com/id/urn:aaid:sc:US:56bcc2db-5a26-4dc9-be99-111d10008308