What causes glaciers to form?

Glaciers form in regions where snowfall exceeds snowmelt over long periods. Layers of snow accumulate, compressing the lower layers into dense ice. As the weight increases, the ice begins to flow slowly downhill due to gravity. Glaciers are most common in polar regions and high-altitude mountain ranges, where cold temperatures preserve the ice year-round. They play a critical role in shaping landscapes and acting as reservoirs of freshwater.