In the SAFe work item hierarchy, Epics are decomposed into what?

In the SAFe work item hierarchy, Epics are decomposed into Features. Features are a collection of stories that together deliver a larger, more significant capability. They are defined at the Program level and are intended to be delivered by an Agile Release Train (ART) in a single Program Increment (PI). This hierarchical structure ensures that large, complex work items (Epics) are broken down into smaller, more manageable pieces (Features) that can be completed by teams within the ART12.