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The relaxor ferroelectrics with known giant piezoelectric and electrocaloric effects make attractive in various technical applications.These effects originate from its abnormal temperature and frequency-dependent dielectric properties.Accumulative experiments indicate that the unusual dielectric response mainly results from reorientation dynamics of interacting polar nanoregions (PNR).We adopted a master equation approach to investigate how the PNR dynamics influences the static and dynamic dielectric response.The PNR reorientation dynamics is thermally activated with a broad distribution of activation barrier.The activation barrier takes into account the contribution of the temperature, applied electric field and the PNR interactions.The Vogel-Fulcher temperature dependency of the PNR-reorientation frequency is found to emerge naturally.The calculated temperature and frequency dependence of the dielectric response is in striking agreement with recent experimental data.