A direct relation does exist between the individual frames and the display time as seen in figure 2. Cartographic animations are often categorized in temporal and non-temporal animations. In the first category display time is used to visualize real world time in a temporal sequence. In the second category display time is applied to explain spatial relations by presenting individual images in logical sequence. When dealing with a temporal animation a direct relation between display time and world time exists.
World time is the time scale of reality, the moment an event takes place in the real world.
Examples of these animations are those of the Dutch coastline from Roman times until today, boundary changes in Africa since the second World War, or the changes of yesterday's weather. Time units can be seconds, weeks, or years. Temporal animation can also deal with time aggregates, for instance display weekly cycles. Those three different types of time were already recognized, although not explicitly, by the cartographer working on topographic maps. Temporal animations show change, change of the locational or attribute component of spatial data.