Here's Apple's abstract: "The present invention creates a model that maps object classes in an object-oriented environment to a data source. The model maps the relationship between properties of each object class and data of the data source. The present invention can be used with a data source such as a relational database, user interface, file system, or object-oriented database. An application's object classes and data source schema are designed independent of the other since the model can be used to map one to the other. The model is comprised of entities and attributes. An entity maps to an object class and to at least one table of the DBMS. An entity contains attributes either simple or derived. A simple attribute maps to a DBMS column. A derived attribute is a combination of other attributes and does not directly map to a DBMS column. A relationship creates a link between entities of the model. A relationship can be used to flatten an attribute or flatten a relationship. A flattened attribute is an attribute of one entity that is added to another entity. A flattened relationship is created by the elimination of intermediate relationships between two entities. Relationships can be either unidirectional or bi-directional. A unidirectional relationship has a single traversal path that has a source entity and a destination. A bi-directional relationship has two traversal paths. A reflexive relationship can be created using a single entity. The model is used to synchronize object properties and the data of the data source."

In other words, the invention creates a model that is used to transparently map object classes in an object-oriented environment to a data source. The model maps the relationship between properties of each object class and data of the data source. For example, the model provides a mapping of the relationship between properties of each object class and columns of DBMS tables. Other data sources that can be used with the present invention include a user intrface, a file system, and object-oriented database, for example. The inventors are Richard Williamson, Linux Upson, Jack Greenfield and Daniel Willhite.