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Data Modeling

The data modeling tool is like the class modeling tool in that you can, for example, lay out a diagram to represent your model visually, but different in that it deals with entities and the relationships between them, not with classes and hierarchies. There is not necessarily a 1:1 relationship between entities and classes—for example, the same class may be used to represent more than one entity. For more about data modeling, see [Modeling Document].

More importantly, however, you use the data modeling tool to define what is in effect a source file—a schema for Core Data. The data model ultimately becomes part of your build product and is used by your application at run time. Instances of entities are typically stored in a persistent store (typically a file).

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