Ferroic domains, intrinsic to various ferroic materials, are pivotal in dynamic responses to external mechanical, electrical, and magnetic stimuli. These domains offer profound insights into fundamental material properties due to their intimate coupling with order parameters. Recent advancements in thin-film growth techniques have led to the discovery of novel domain structures within superlattice heterostructures, marking a significant evolution in the study of ferroic domains. Synchrotron X-ray diffraction, characterized by its high coherence and brilliance, has been instrumental in advancing our understanding of ferroic domains and their dynamic behavior. This technique enables the precise measurement of domain diffuse scattering, allowing for the determination of domain periodicity, coherence, orientation, and their dynamic responses under applied fields. In this chapter, we offer an introductory guide to the fundamental concepts of ferroic domains and superlattice heterostructures, alongside an overview of synchrotron X-ray diffraction techniques. We provide practical guidance on the measurement and analysis of X-ray diffraction and domain diffuse scattering data. Additionally, we present exemplary research studies, detailing the characterization of parameters relevant to ferroic domain structures, thereby illustrating the application of these techniques in contemporary research.