This means that at each point in the map it seems as if one looks straight down to the earth's surface. However, sometimes a non-orthogonal view better explains the spatial relations. This will for instance result in the use of cross-sections or perspective views. In the map point, line and area symbols as well as text represent the geographic phenomena displayed. In most maps a combination of these basic graphical elements can be found.
Maps are only useful if the user is able to judge the value of the contents.
Important elements are a scale indicator, the legend and the north arrow.