Mountains are formed due to large scale movements of the earth's crust and the collision of the tectonic plates. Over the history of earth - 9 such movements have taken plates which have resulted in formation of large mountains and mountain ranges.

Broadly they can be classified into 5 major categories:

Volcanic Mountains:

• These mountains are formed due to collision of tectonic plates and movement along the plate boundaries which erupt to formed mountains.
• Most important types of Volcanic Mountains are : Composite cones or Stratovolcanoes and Shield Volcanoes.
• Mount Fiji and Khilimanjaro are Stratovolcanoes while Mauna Loa on Hawaii is a Shield Volcano.

Fold Mountains:

• These are formed due to large scale collision of tectonic plates which results in subduction and folding to form mountains
• Balkan Mountains, Jura, Zagros mountains are some examples

Block Mountains:

• These are formed When a fault block is raised or tilted.
• Higher blocks are called horsts and troughs are called grabens
• Examples include Sierra Nevada Range, Rhila Rhodope mountain range etc.

Residual Mountains:

• Residual mountains are formed as a result of erosion of an existing elevated area.
• Examples include the Aravalli Range, Nilgiri Mountains, Eastern and Western Ghats.

Mountains can also be classified basis origin and mode of origin and period and the location.