Model validation is a methodological approach used to assess the degree to which a computational, mathematical, or conceptual model accurately represents the real-world system or phenomenon it is designed to simulate or predict. This process investigates the model's reliability, predictive accuracy, and generalizability by comparing its outputs and structure against empirical data, independent observations, or established theoretical principles using various quantitative and qualitative metrics. Its significance lies in establishing the trustworthiness, credibility, and applicability of models for scientific understanding, engineering design, and informed decision-making.