Core Data supports several store types: three for saving and loading data (SQLite, XML, and Binary), and a fourth for caching applications, In-Memory. The Xcode Core Data application template allows the user to choose between the persistence formats in the File Format pop-up button on the save panel.
Which should you use?
Each of these types has their strengths, but we recommend SQLite for most
it is fast, thanks to its support for incremental updates,
and moderately readable – you can open the file in the
sqlite3 command-line utility should you need to peek
inside the store.
The XML format can be inspected too, but it is significantly slower than SQLite.
Note that Core Data is not a database ...