The word “structure” comes from Latin struere which means to build, to arrange, and contains the notion of an organised thing. Spatial structures exist, because geographical space is not constituted by a set of unique places, occupying random locations. The successive choices of actors and, more broadly, the answers given by societies to the issue of space control , obey to certain logics, even if the overlapping and interweaving of these logics make their legibility more or less evident;
The geographer interprets regularities in distribution and arrangement of geographical objects on Earth’s surface. These spatial arrangements which constitute spatial structures, are outcomes, most of the time unintentional but whose relative stability ends up in imposing itself upon the actors.
However, a spatial structure should not be interpreted only in a geometric or morphologic sense. A spatial structure is completely described only if, beyond the form taken by the arrangement of objects, it is possible to figure out the inter-dependencies among the latter. A pole does, of course, correspond to a concentration of population and activities represented on a map through a thicker point, it is also a place of attraction and diffusion (spatial diffusion). The relationships it maintains with the other places are a part of the definition of its situation and attributes.
If geographical space is considered as a set of interacting elements, spatial structure must be understood as the principle of organisation of the geographical entity under study, which is materialised under a form (axis, gradient, pole, etc). Through this, spatial structures belong to the theoretical field of systemic and modelling. In the domain of graphical semiology, the combination of several elementary structures, called chorems, produces a graphical model.