A Glacial Period is a time in Earth's history when large areas of the planet are covered by ice sheets and glaciers. These periods are part of the broader cycle of ice ages, which are characterized by significant drops in global temperatures. During a glacial period, the climate becomes colder, leading to the expansion of ice in polar regions and the movement of glaciers into lower latitudes. The most recent glacial period, known as the Last Glacial Maximum, occurred around 20,000 years ago. During this time, ice sheets covered much of North America, Europe, and Asia. As the climate warmed, these glaciers began to retreat, marking the transition to the current interglacial period, known as the Holocene.