The field configuration page allows you to edit the attributes from your data that are exposed through the REST services.
Set the filter expression if you would like some of your data automatically filtered from query results. String fields must be contained in single quotes.
Alias The alias is the name that gets exposed through the services. Changing the alias allows you to display something different than the table field name in the REST output.
Included and Editable You can choose to exclude fields from the database and also select if they are editable through the feature service.
Display Field Setting the display field allows you to set the default field for labels.
Sync Table Schema Your data schema may evolve e.g., database field names change, fields are added and dropped. When that happens you can sync your database schema with the Sync Table Schema button to synchronize your layer fields from the database table.