We have discussed databases in general (a medium containing numbers, symbols, or graphics organized according to some scheme). And we have commented on the idea of spatial data (data describing entities in the three-dimensional world where the location of the thing being described is an integral part of the description.) A spatial database, then, is a collection of spatial data, organized in such a way that the data can be retrieved according to their locational identifiers and in other ways as well.
This presentation of a list of data types or variables whose data might be stored in a spatial database does not imply that satisfactory storage schemes are easy to determine, nor that each variable will be stored in the same manner. Whether the geometric abstraction for a data type is best selected as a point, line, area, or volume can be an important consideration in a particular storage scheme.
The development of spatial databases to be used for analysis and decision making is both an art and a science. Thus, when any data-handling program is being developed, a key point to remember is that there is no single best way.