Fluid-fluid interfacial area is a key parameter in understanding various multiphase flow systems, including oil-water mixtures in oil recovery processes, gas-liquid mixtures in chemical reactors, and air-water mixtures in environmental remediation. The interfacial area represents the surface area per unit volume where two immiscible fluids come into contact with each other. This area plays a crucial role in determining mass transfer rates, phase dispersion, and overall system behavior. Researchers study fluid-fluid interfacial area to optimize processes, enhance efficiency, and improve understanding of complex multiphase systems. Advanced imaging techniques and mathematical models are often used to quantify and analyze interfacial area in different applications.