Page "Database" Paragraph 89

A data model is an abstract structure that provides the means to effectively describe specific data structures needed to model an application.

As such a data model needs sufficient expressive power to capture the needed aspects of applications.

These applications are often typical to commercial companies and other organizations ( like manufacturing, human-resources, stock, banking, etc .).

For effective utilization and handling it is desired that a data model is relatively simple and intuitive.

This may be in conflict with high expressive power needed to deal with certain complex applications.

Thus any popular general-purpose data model usually well balances between being intuitive and relatively simple, and very complex with high expressive power.

The application's semantics is usually not explicitly expressed in the model, but rather implicit ( and detailed by documentation external to the model ) and hinted to by data item types ' names ( e. g., " part-number ") and their connections ( as expressed by generic data structure types provided by each specific model ).