A mountain is a landform that extends above the surrounding terrain in a limited area. A mountain is generally higher and steeper than a hill, but there is considerable overlap, and usage often depends on local custom. Some authorities define a mountain as a peak with a topographic prominence over a defined value: for example, the Encyclopædia Britannica requires a prominence of 2,000 feet (610 m).

24% of the Earth's land mass is mountainous; 1 in 10 people live in mountainous regions. All the world's major rivers are fed from mountain sources, and more than half of humanity depends on mountains for water. [1]

The adjective montane is used to describe mountainous areas and the things associated with them.