Field: A column in a table that describes an attribute of a spatial feature.
Flat file: A database that contains all data in a large table.
Foreign key: One or more attributes in a table that match the primary key in another table.
Hierarchical database: A database that is orga nized at different levels and uses the one-to-many association between levels
Interval data: Data with known intervals between values, such as temperature readings.
Join: A relational database operation that brings together two tables by using keys or a field com mon to both tables.