This chapter delves into the core principles of petro-physical properties and rock physics, forming the foundation for advanced reservoir characterization and seismic interpretation. By examining the elastic properties of rocks—such as Young’s modulus, shear modulus, bulk modulus, and Poisson’s ratio—the chapter explains how rocks respond to seismic waves and stress. Additionally, key properties like porosity, permeability, and fluid saturation are explored for their critical roles in predicting reservoir behavior, essential for energy exploration and production. The chapter also introduces rock physics models, including Gassmann’s equations for fluid substitution and Biot’s theory of poroelasticity. These models enhance seismic interpretation and inform practical applications, from lithology prediction to reservoir management. A section on Carbon Capture, Utilization, and Storage (CCUS) underscores the importance of petro-physical properties in identifying storage sites and monitoring CO2 sequestration. Finally, the chapter addresses unique geological settings—such as deltas, salt domes, and clastic reservoirs—illustrating how petro-physical properties shape exploration strategies. Emphasizing the convergence of rock physics and seismic interpretation, the chapter advocates for continued innovation and collaboration between academia and industry to meet the dynamic challenges of the energy sector.