They are graphics that are made in the form of a map, indicating the different areas according to their characteristics and the quantities according to their representation, that is, they represent the geometric units and their attributes as they are exposed in the area, only showing the changes that depend on the increase, for example by not representing the geographical space but the number of inhabitants it has if it is a cartogram of a country. Cartograms do not represent the reality of the physical space of a certain area, it can be very similar or it may not have any resemblance to real space.
We found 3 main types of cartograms, each one differentiated by the way they show the objects, their zones and the numerical units in their distances, these are the continuity cartograms, the continuity cartograms and the cartograms of Dorling. Those that have continuity are those that make the map seem more real, due to the way that in their internal units they are closer in their boundaries, thus they maintain a relationship between the limits and their borders, but that in their internal part they are may distort, making its divisions unrecognizable.
Those that do not have continuity do not maintain a connection to their nearby elements, differing because they can grow or decrease in size, but still maintain their shape, a characteristic that stands out is that it makes them easy to build since they preserve their geometric shapes The objects or elements, even so, do not maintain the nature of the continuous form of the geographic space, making it very difficult for it to remain complete for a study area.
Dorling's cartograms do not maintain the conventional forms neither inside nor outside, with their boundaries of objects or elements, it does not enlarge or shrink as in the previous cases but instead places the geometric forms on bases of mere uniform circles, that the size to the proportion of the same represents the numerical value that represents the zone or area. Cartographic communication is impressive even though it is difficult, since the reader must have a broad knowledge of the area represented, but even so it is still an excellent mode of real geographical distribution.
