An icefield is a large area covered by ice and snow, typically found in polar regions or high mountain ranges. Icefields are formed from accumulated snowfall that compresses into ice over time. They can feed glaciers, which are moving rivers of ice that flow down valleys. Icefields play a crucial role in the Earth's climate system by reflecting sunlight and regulating temperatures. They also serve as important freshwater reservoirs, releasing water as they melt. Notable examples of icefields include the Patagonian Icefield in South America and the Columbia Icefield in Canada.