Overview of content entities and fields.
Fields are the building blocks of Drupal's powerful content modeling system. The Field API allows for the development of custom field types, field widgets, and field formatters to suit almost any data display and collection needs. When combined with entities, which allows for the attachment of fields to entity bundles (commonly known as content types), Drupal becomes infinitely flexible without requiring writing any code.
- Understand how the main components of Drupal's field system fit together
- Learn how fields can be used to customize your site
- Customize existing fields and create new additional functionality within your own modules
At this point in the development cycle, the Field API is stable. Contributed modules that provide additional field types and add functionality to the field system are likely to emerge, but the main components of the core functionality are unlikely to change. Resources labeled with Drupal 8 should apply to Drupal 9.
Fields for site builders
Field API for developers
Fields and Entities are closely related concepts. It is best to learn both.