Contains a set of fields and methods common to items of any app (see BaseApplicationItem). This set can be extended with fields and methods specialized for items of specific apps..

Contains a set of fields and methods common to reference objects of any app item (see. BaseApplicationItemRef). This set can be extended with fields and methods specialized for reference objects of specific app items.
Reference objects are generally used in App type properties to avoid loading all related data at once. To retrieve the full data of an app item, you need to call the method BaseApplicationItemRef.fetch and obtain the full object of the item ApplicationItem.

const  my_app_full = await Context.data.my_app.fetch();

Item with data from the selected fields. Contains a set of fields and methods common for object references to an item of any app. For more details, see BaseApplicationItemRef. Includes only field data defined by the partial load rule as well as the required __id field. T – Base app field set. P – Structure of additional app parameters. S – Object with partial field load rules.

Contains only the fields defined in the partial loading rule, as well as the mandatory __id field.