Which is a main element of FirePOWER Device Manager?

FDM is specifically architected as an on-box management solution embedded directly on Firepower Threat Defense appliances, accessible through a local web browser interface. This distinguishes it from Firepower Management Center (FMC), which is an off-box centralized manager. The on-box, web-based nature is the primary architectural element that defines what FDM is as a product.

Streamlined user experience is a general benefit or marketing descriptor, not a defining architectural element of FDM.

Simplified interface is a qualitative characteristic of FDM's UI design, not a main structural or functional element of the product.

Cloud-based policy orchestration describes a separate product category such as Cisco Defense Orchestrator, not FDM, which operates locally on the device.