Characteristics of an Application Module
The application module acts as a wrapper for the views and entities in your business model. It also handles all database transactions and performs tasks that are specific to the application. An application module performs a specific application task—for example, logging service requests or processing user information. An application module has these main characteristics:
It represents the data model that your client uses and has one connection to the database.
It enables you to gather data customized to a client interface (such as a form), so that data can be retrieved in one network round-trip instead of multiple trips.
It can contain other application modules, called nested application modules, enabling you to separately develop, test, and then reuse application module functionality.
It keeps track of all changes that affect data in the database and defines the transactional model.
It provides remotely accessible methods, which implement the application module behavior.
You can deploy the same application module in multiple configurations.
As discrete units, application modules are easily reused in the business logic tiers of other applications.