Plate tectonics
The large scale motions of the earth’s lithosphere are describe by a scientific theory called plate tectonics which explains that Earth's outer layer is made up of plates, which have moved throughout Earth's history. The theory was developed during first decade of 20th century (by a famous advocate Alfred Wegener) on the older concept of continental drift and was accepted by many geoscientific communities.
There are currently seven major and many minor plates are present in the case of earth. These plates move in relation to one another at one of three types of plate boundaries: convergent or collisional boundaries; divergent boundaries, also called spreading centres; and conservative transform boundaries. Activities like earthquakes, volcanic activity, mountain building and oceanic trench formation occur along these plate boundaries and the lateral relative movement of the plates varies 0-100 mm annually.
Relation between plate tectonics and mountains:
Mountain formation processes are associated with large scale movements of tectonic plates. The formation of mountain ranges occurs by means of lateral movements as opposed to vertical ones. Mountain formation is related to plate tectonics, folding, faulting, volcanic activity; igneous intrusion and metamorphism are all parts of the organic process of mountains building.
There are three main types of mountains: volcanic, fold, and block.
Volcanic Mountains: movements of tectonic plates create volcanoes along the plate boundaries which erupt and form mountains.
Fold Mountains: when plates collide and ride on one over another, the plates tend to buckle and fold forming mountains.
Block Mountains: The Block Mountains can result when a fault block is raised or tilted. Strong tensional forces caused by spreading apart of surface causes a plate to split apart such that a centre block will drop down relative to its flanking blocks.
(Ref: