Before getting started with Core Data, you should take a look at how we will organize or design the data models and determine the relations between these models. The data model in Core Data is called Entity.
Xcode provides an editor to add entities and to specify the relations between them. The design of your data models should be simple and organized, so anyone looking at it should understand what is going on between your data models and what the relations are between them. Check the following example of a design of data models:
The example shows four entities and the relations between them. The first entity is a
Chef entity, which has a list of attributes, such as
lastName. It has a one-to-many relation to the
Recipe entity, as each
Chef can have many recipes but each recipe has only one chef. The same idea applies to other entities and, through attributes and relations, you will understand the relations between entities.