This chapter discusses and reviews the diverse approaches presented in this book to periodizing Big History by integrating frameworks rooted in complexity, information, energy flow, and evolutionary patterns. The chapter points out that this volume is unique because it brings together a wide range (but not all) of approaches to Big History periodization, something not done before, demonstrating how important, diverse, and useful the process of periodization is. Highlighting the interplay of cosmic and terrestrial dimensions, the contributions showcase various methodologies, from thermodynamic steady-states to networked cooperation, while emphasizing the absence of a universal periodization framework. Instead, the studies underline how distinct criteria—spanning matter, consciousness, and social evolution—offer unique perspectives on historical phases. While the approaches agree that complexity generally increases over time, this progression is neither deterministic nor uniform, and humanity now faces critical junctures that could either continue or reverse this trend. By presenting innovative frameworks and methodologies, this work illuminates the multifaceted nature of Big History and provides tools to better understand its intricate evolutionary trajectories.