An inductor using a core to increase inductance will have other losses in the core, such as hysteresis and eddy current losses, in addition to wire resistance, that are also represented as a higher ESR.
An inductor using a core to increase inductance will have other losses in the core in addition. This is to wire resistance. This is such as hysteresis. This is such as eddy current losses. Wire resistance are also represented as a higher ESR.