How is the data model or business logic typically structured in a project?

In Android projects, data models and business logic are usually structured using architectural patterns such as MVVM or MVP.

The following layers are often distinguished:

• Data Layer — responsible for obtaining and storing data (e.g., repositories, data sources, databases).
• Domain Layer — contains business logic and rules, often implemented through use cases or interactors.
• Presentation Layer — responsible for displaying data and user interaction (View, ViewModel, or Presenter).

This separation allows isolating business logic from UI implementation details and data sources, making testing and maintenance easier.