A cartogram is a type of graphic that depicts attributes of geographic objects as the object's area. Because a cartogram does not depict geographic space, but rather changes the size of objects depending on a certain attribute, a cartogram is not a true map. 
Cartograms vary on their degree in which geographic space is changed; some appear very similar to a map, however some look nothing like a map at all. There are three main types of cartograms, each have a very different way of showing attributes of geographic objects- Non-contiguous, Contiguous and Dorling cartograms.
Cartograms vary on their degree in which geographic space is changed; some appear very similar to a map, however some look nothing like a map at all. There are three main types of cartograms, each have a very different way of showing attributes of geographic objects- Non-contiguous, Contiguous and Dorling cartograms.