Surface and interfacial phenomena as a research area encompass the study of physical, chemical, and physicochemical processes occurring at phase boundaries, including solid–liquid, solid–gas, liquid–gas, and liquid–liquid interfaces. This field investigates adsorption, wetting, adhesion, capillarity, surface tension, interfacial rheology, and related equilibrium and non-equilibrium behaviors. It integrates thermodynamics, statistical mechanics, spectroscopy, microscopy, and simulation to elucidate structure–property relationships at interfaces. Research in this area underpins advances in catalysis, colloid and dispersion stability, electrochemistry, nanomaterials, biomembranes, microfluidics, and advanced coatings, with emphasis on how interfacial structure, composition, and energetics govern macroscopic material performance and functionality.