This begins a three-unit section covering some basic principles of spatial databases. As these issues are fundamental, many of them are introduced here but dealt with in much greater detail in later units. Elements of databases are introduced, including the entity-object distinction, classes, attributes, layers and database models. The unit concludes with a discussion of database design, including the process, desirable database characteristics and issues.

This unit continues the development of basic concepts about representing reality as spatial data. Here we look at how the representation of reality in the form of entities is handled with the spatial objects points, lines and areas.