Defines field, widget, display formatter, and storage types.
In the Field API, each field has a type, which determines what kind of data (integer, string, date, etc.) the field can hold, which settings it provides, and so on. The data type(s) accepted by a field are defined in hook_field_schema().
Field types are plugins annotated with class \Drupal\Core\Field\Annotation\FieldType, and implement plugin interface \Drupal\Core\Field\FieldItemInterface. Field Type plugins are managed by the \Drupa