The Preclassic Period, also known as the Formative Period, refers to the time in Mesoamerican history from around 2000 BCE to 250 CE, during which early complex societies developed in the region. This period laid the groundwork for later Mesoamerican civilizations, such as the Olmec, Maya, and Aztec, showcasing advancements in agriculture, architecture, and social organization that would shape their future trajectories.