In mobile apps, you may need to save data locally in device disk-like files or database files. In a database, you can save a set of records (objects) and create relations between them. You can perform many types of operations with high performance, such as insertions, deletions, updates, fetching, filtering, and so on. Initially, we used to use SQLite to manage persistence in an iOS app, until Apple launched the Core Data framework.
Core Data is a great framework that manages the data layer of your application and model objects, persistence in device disk. Core Data is built over SQL, but it provides more features and a higher level of abstraction. In this chapter, we will build a simple Todo app. This app will teach you how to design data models with Xcode editor, add new records to Core Data, fetch and display the inserted records from Core Data, delete records from Core Data, and so on.