For the safe and cost-effective design of critical infrastructure such as dams, nuclear power plants, and long-span bridges, it is essential to estimate earthquake ground motions in a site-specific manner accurately. This estimation process involves conducting a seismic hazard analysis tailored to the project site of interest. Seismic hazard assessment is the methodology used to evaluate the seismic design parameters that dictate the ground motion intensity for such structures. Seismic hazard assessment could be approached through two primary methods such as deterministic and probabilistic frame work. However, deterministic method focuses on a specific earthquake scenario as well as designing the structure to withstand a maximum considered earthquake. In contrast, Probabilistic method accounts for the uncertainties in earthquake size, location, and frequency of occurrence, recognizing that the expected lifespan of a structure becomes often much shorter than the recurrence interval of major seismic events. This paper reviews the methodologies involved in seismic hazard assessment, emphasizing developing a Uniform Hazard Spectrum (UHS) in the frequency domain analysis. The UHS serves as a critical tool for deriving seismic design insights, ensuring that structures meet safety standards by accounting for both the severity and the probability of earthquake events.