What are the two main types of glaciers?

The two main types of glaciers are described as alpine glaciers and ice sheets. Alpine glaciers, also known as mountain glaciers, form in mountainous regions and flow down valleys typically shaped by previous glacial activity. They are characterized by their smaller size compared to ice sheets and are found in areas where conditions allow for their formation at high altitudes.

On the other hand, ice sheets are vast expanses of glacial ice that cover large land areas, significantly more extensive than alpine glaciers. They typically form in polar regions and can be several kilometers thick, such as the Antarctic and Greenland ice sheets. Ice sheets represent a larger and more significant part of Earth's freshwater storage.

This distinction highlights the varying environments and characteristics that differentiate these two types of glaciers, making the answer identifying them as the main types accurate. The other options do not adequately categorize glaciers or refer to types that are more specific or less commonly recognized in the context of physical geography.