The Preclassic period refers to the initial stages of development of various ancient civilizations, particularly those in Mesoamerica and the Andean region. This period typically spans from around 2000 BCE to 250 CE. During the Preclassic period, various societies began to establish complex agricultural systems, social hierarchies, and monumental architecture. Important cultural developments, such as the invention of writing systems and the creation of religious beliefs and practices, also emerged during this time. Archaeological evidence from this period provides invaluable insights into the origins and early evolution of these ancient civilizations. Scholars study artifacts, monuments, and settlements to better understand the societal organization, economic activities, and belief systems of Preclassic societies. Overall, the Preclassic period laid the foundation for the flourishing of advanced civilizations in Mesoamerica and the Andean region in later periods, such as the Classic and Postclassic periods.