This indicates how the underlying vNIC or vHBA for this virtual interface was instantiated - for example statically defined versus dynamically created, as with dynamic vNICs for VM-FEX. This distinction matters to an admin because dynamically instantiated VIfs are typically created and torn down automatically by a VM-FEX or hypervisor integration rather than manually by an admin, so an unexpected VIf appearing or disappearing is expected behavior under dynamic but would be alarming under static. A value of 'dynamic' here would be normal for a VIf tied to a VM's dynamic vNIC under VM-FEX, appearing and disappearing as VMs migrate.