The 1980-1986 period witnessed the consolidation of the cold dark matter paradigm as the engine of hierarchical structure formation, with non-relativistic dark matter driving galaxy assembly and large-scale clustering in ways that aligned theory with observations. The era also foregrounded viable particle candidates such as invisible axions and initiated explorations into their cosmological production and relic abundance, bridging particle physics with cosmology. Direct-detection concepts and the exploration of non-particle dark matter components began shaping experimental approaches. Historical Significance: This period established the cold dark matter paradigm as the default framework for simulations and cosmological modeling, guiding decades of parameter studies and predictive work on structure growth. It also launched axion dark matter as a central particle candidate, formalizing cosmological production and relic abundance calculations, while complementary ideas such as quark nugget dark matter and early direct-detection proposals broadened the theoretical landscape and seeded experimental efforts.