Bundles allow you to have different variations of a content entity. All bundles share the same base field definitions but not configured fields. This allows each bundle to have its own custom fields. Display modes are also dependent on a specific bundle. This allows each bundle to have its own configuration for the form mode and view mode.
Using the custom entity from the preceding recipe, we will add a configuration entity to act as the bundle. This will allow you to have different message types for multiple custom field configurations.
We will need a custom module to place the code into to implement a configuration entity type. Create an src
directory for your classes. We need a custom content entity type to be implemented, such as the one in the Creating a content entity type recipe of this chapter.