There are a variety of glacier types and the places they form vary as well.
Alpine (or mountain) glaciers include varieties that form directly on mountains, while continental glaciers, also known as ice sheets, cover the terrain surrounding it. See more on continental glaciers below.
Mountain glaciers are smaller glaciers that form at higher altitudes and often occupy the naturally-found crevices or depressions found on the sides of mountains.
These types of glaciers look like frozen rivers of water extending down the sides of mountains, sometimes all the way down to sea level.
Another type of glacier that forms on mountains, these ones fill in bowl-shaped impressions and are wider, as opposed to being long like the Valley Glaciers.
These glaciers cover at least 19,000 square miles (50,000 sq km) of land. While Valley Glaciers flow downhill within the confines of a valley and sculpt the land into rugged terrain, Continental Glaciers flow outward in all directions, often smoothing out the land beneath it.
Massive expanses of ice that are over 19,000 feet (50,000 sq km) are known as Ice Sheets. Currently, the only Ice Sheets are found in Antarctic and Greenland.
Ice Sheets that extend from the land and float on the water are known as Ice Shelves. Most of Antarctica is surrounded by Ice Shelves.
Ice Caps are relatively flat and cover less than 19,000 square miles of land area.