Watch this space for possibly a long time! content yet to come down the line...
In meantime see page including links on computing.
Maps are scale representations of reality mostly in plan (2D) format originally on paper with a fixed scale where one unit on paper matches a scale multiple of this in reality but now computer models held in GIS. There are allways judgements to be made on what is on the map, and like statisics maps can lie or at least decive.
Map Links: