Continental features that are classified in the second order of relief include continental masses, mountain masses, plateaus, plains and lowlands. A few examples are the Himalayas, Alps, Rocky Mountains, Andes, Tibetan plateau, plateau of Anatolia (Turkey), Indo-Gangetic plains, Siberian lowlands and the plains of Mississippi. The great rock cores (shields) that form the heart of each continental mass arc of this order.
In the ocean basins, the second order of relief includes continental rises, slopes, abyssal plains, mid-ocean ridges, submarine canyons, and subduction trenches.
Mountains can be defined as a large natural elevation of the earth’s surface rising abruptly from the surrounding level.
Plateau is extensive area of flat upland usually bounded by an escarpment (i.e., steep slope) on all sides but sometimes enclosed by mountains. The essential criteria for plateaus are low relative relief and some altitude.
In geography, a plain refers to a flat area with little or no changes in elevation. It is one of the world’s major landforms.