What is Core Data? You'll hear a variety of answers to this question: It’s a
database! It's SQLite! It's not a database! And so forth.
Here's the technical answer: Core Data is an object graph management and
persistence framework in the OS X and iOS SDKs.
That means Core Data can store and retrieve data, but it isn’t a relational database
like MySQL or SQLite. Although it can use SQLite as the data store behind the
scenes, you don’t think about Core Data in terms of tables and rows and primary
Imagine you’re writing an app to keep track of dining habits. You have a varied set
of objects: restaurant objects, each with properties such as name and address;
categories, to organize the restaurants; and visits, to log each visit to a restaurant.