A glacier is a persistent, massive body of dense ice that forms over centuries from accumulated snow and constantly moves downhill under its own weight, sculpting striking landforms like fjords and cirques. While 99% of glacial ice resides in vast polar ice sheets, notably in Antarctica and Greenland, glaciers are also found in mountain ranges on every continent except mainland Australia, with Pakistan boasting over 7,000 glaciers—the most outside the polar regions. These colossal ice formations are Earth's largest freshwater reservoir, holding approximately 69% of the world's freshwater, and serve as vital water sources for numerous ecosystems and human populations. Crucially, glaciers act as sensitive indicators of climate change, with their mass fluctuations directly reflecting shifts in global temperatures and precipitation. Their characteristic blue color is due to water molecules efficiently absorbing other colors and the intense pressure within the ice squeezing out air bubbles.