ABSTRACT
Atlases are intentional combinations of maps or data sets, structured in such a way that specific objectives are reached, using a narrative or even a scenario. Atlas access and navigation are key aspects to reach these objectives, and the main purpose of atlases is to convey information through the comparison of the various maps contained in them.
Nowadays, most atlases are being published as web atlases, providing online links to spatial databases, and the various possible functionalities of these atlases are listed. They are related to map machines, which lack the narrative of atlases proper, and to story maps (pre-programmed templates in which spatial data can be visualized).
After this discussion of atlas characteristics, the ways they work and help us in explaining patterns, in comparing and analysing data sets and in spatial decision-making are explained, discussing all the possible map-use tasks.
