There are three main types of landforms throughout the earth: plains, mountains, and plateaus. They differ in their physical appearance, elevation above sea level, and location on their respective continent.
Plains are flat land areas without significant topographical rises in elevation. They may be located near coastlines or within continental interiors. The Great Plains area in the interior United States is a great example.
Mountains are raised land forms, the result of convergent crustal activity resulting in protrusions that may reach thousands of feet into the atmosphere. Mountains may exist as a singular mountain, or the result of chain activity. The Adirondack mountains in the eastern United States are a good example.
Lastly, plateaus are raised landforms that are flat on the top. It is as if someone cut off the top peak of a mountain, leaving a flat top to the raised elevation. The Colorado Plateau in the western United States is a superb example, with the Grand Canyon right in the middle of it.