Mountains are classified as

Block Mountains. These are also known as Fault Block Mountains, as they are the result of sliding of rocks along the fault lines of earth crust.Seira Nevada USA, black forest mountains of Europe.

Folded Mountains: These Mountains are the results of collision of tectonic plates, resulting in the formation of folded mountains. Eg: Himalayas, Ural, Rockies.

Volcanic Mountains: Mountains formed due to volcanic eruptions. Eg: Fujiyama of Japan, Cotopaxi of Equador.

Relict Mountains: When orginal mountains are eroded by the agents of gradation, they become relict mountains.Eg: Vindhyas, Aravallis, Satpura, Eastern Ghats, Western Ghats, Parasnath in India