A glance at a topographic map of any territory allows us to distinguish the large relief or physiographic units that make it up. All of them are the result of the geological processes that have acted in this sector of our planet. They are the consequence of a particular geological history.
Usually, the origin of the main relief structures is influenced by tectonic processes. In emerged areas, plate tectonics, thermal flow and isostatic readjustments are responsible for the formation and architecture of mountain ranges, massifs, mountain systems, depressions ... External geomorphological processes, on the other hand, are the cause of the most superficial modeling forms that characterize a landscape.
When someone wants to make an approach to the geological knowledge of a place to observe in detail outcrops, structures, forms or active processes, it is essential to place them in the context of the unit of relief in which they are found and the sequence of episodes that have originated it.