Glacial erratics are large boulders that have been transported and deposited by glaciers. These rocks can be found far from their original location, often sitting on different types of bedrock. They vary in size and composition, reflecting the geological diversity of the areas where they originated. As glaciers advance and retreat, they pick up rocks and debris, which are then carried along. When the glacier melts, these erratics are left behind, providing valuable information about past glacial movements and the Earth's climate. Studying glacial erratics helps scientists understand the history of glaciers and their impact on the landscape.