Features of the relief of North America. How are they explained?

North America is a mainland with an area of ​​over 24 million square kilometers. It is washed by as many as three oceans: the Arctic, Atlantic and Pacific. The coastline of the mainland is quite indented by river deltas, bays and tributaries, this is especially noticeable on the western and northern coasts. In the west of the mainland, there are also huge mountain ranges, such as the Cordillera, Rocky Mountains and others, smaller in size. All these mountain systems stretch from north to south. In the east of North America, on the contrary, plains are widespread here, they attach to the Gulf of Mexico, the Atlantic coast, to the northern lakes and large bays.