Fluid Catalytic Cracking (FCC) is one of the principal conversion processes in modern petroleum refining, enabling the transformation of heavy petroleum fractions into high-octane gasoline and light olefins. The growing global demand for transportation fuels and low-carbon chemical feedstocks requires further optimization of both the efficiency and selectivity of FCC technology. The technological and economic performance of the process is determined directly by the structural properties of the catalysts used, the nature and distribution of acid sites, and the architecture of the pore system. The historical development of FCC catalysts has been characterized by a transition from natural aluminosilicates to synthetic amorphous systems, and subsequently to zeolite-based catalysts possessing high stability and shape-selective properties. This evolution has not only increased catalytic activity but has also enabled the controlled distribution of products and the optimization of selectivity on a mechanistic basis. In particular, the application of USY and ZSM-5 type zeolites has played a key role in increasing gasoline yield, selectively producing light olefins, and controlling hydrogen transfer reactions. The primary objective of this study is to systematically analyze the evolutionary stages of FCC catalysts, explain the mechanisms governing selectivity formation within the context of structure–acidity–reaction mechanisms, and substantiate the relationship between catalyst properties and product distribution within a conceptual model framework. For this purpose, the type and density of acid sites, the influence of pore size on diffusion, the carbocation mechanism, and catalyst deactivation factors have been evaluated analytically. The study is conducted on the basis of systematic literature analysis and theoretical synthesis without performing empirical experiments. The proposed structure–acidity– selectivity model provides a theoretical foundation for future developments in FCC technology, particularly for propylene-oriented processes and the production of environmentally compliant low-emission fuels.