1) Mountain building, or rock deformation, occurs through compressional, tensional, and shear stresses that cause folding and faulting of the Earth's crust. 2) There are three main types of folds - anticlines, synclines, and monoclines - and three main types of faults - normal, reverse, and strike-slip. 3) There are four main types of mountains - folded mountains, fault-block mountains, volcanic mountains, and dome mountains.