Understanding Activity Entities
Activities are a special type of system entity. Create custom activity entities to support your communication needs, including instant messaging (IM) and text messaging (SMS).
Because customizations affect all users, only a user with the System Administrator or System Customizer security role, or equivalent permissions, can make customizations.
The data is split between two entities:
- The Activity entity. The appropriately-named Activity entity stores information used in all activity types, such as the owner of the record. You cannot make changes to the Activity entity.
- Custom activity entities. You create specific custom activity entities, such as E-mail, Task, and Letter. These store information specific to that type of activity. This information could be the courtesy copy (Cc) addresses used in an e-mail message.
When you create a customized activity entity, it is related automatically to the the Activity entity. When creating a custom activity, specify the entity as an activity entity (not to be confused with the Activity entity).
Because you cannot change the Activity entity, you cannot change the Activity entity form. Make your changes to a custom activity entity form.
You can create 1:N (one-to-many) relationships for a custom activity the same as any other activity. Also, you can update existing relationships.