What is Core Data?

Path to Success
The Core Data Programming Guide is primarily a reference volume. You should not simply try to read it straight through to understand Core Data.

To learn about Core Data, you should typically follow this path:

Start by reading the overview in Core Data Basics (in Core Data Programming Guide).
This will give you a basic understanding of what Core Data is and why you might want to use it.

Work through the Core Data Tutorial for iPhone OS.
This provides a good introduction to the fundamentals of application development using Core Data.

Work through the Core Data Utility Tutorial.
This will give you a greater appreciation of the different components of the framework—in particular the managed object model—without the distraction of a user interface.

Work through the tutorial described in Creating a Managed Object Model with Xcode.
This introduces the major user interface elements of, and teaches you how to use, the Xcode modeling tool.

When specific areas need greater explanation, refer to the Core Data Programming Guide.

After you’ve worked through the introductory materials, try creating more complex applications (using, for example, two related entities) as suggested in Core Data Tutorial for iPhone OS. The Core Data Programming Guide will be increasingly useful as you continue your exploration, as will Model Object Implementation Guide and Predicate Programming Guide.

As you progress, it is important to bear in mind that Core Data objects are still just objects, and have little influence on the user interface parts of your application simply by virtue of being Core Data objects. (In fact, the reverse is true—you may find that your user interface affects the way you structure your data.) You should practice creating Core Data applications using traditional Cocoa techniques such as target-action and delegation just as you would in a non-Core Data application.

Core Data in Depth
There are several documents that describe particular aspects of Core Data in greater depth than in the Programming Guide. You should use these documents only when you have a firm understanding of how Core Data works, and then only if and when you need to:

Core Data Model Versioning and Data Migration Programming Guide
Read this document to learn how to support versioning.

Atomic Store Programming Topics
Read this document to understand how to create your own type of persistent store.