In technical terms, a glacier is a perennial mass of ice which moves over land. Glaciers form in locations where the mass accumulation of snow and ice exceeds their recession (or ablation) over many years.

Importantly, glacier ice is the largest reservoir of fresh water on Earth, and is second only to oceans as the largest reservoir of total water. Glaciers cover vast areas of the polar regions and are found in mountain ranges of every continent including Australasia (there are glaciers in New Zealand). In the tropics glaciers are restricted to the highest mountains.

Of course, they are also indicators of climate and climate change.

And, they are gorgeous.