Can you explain what the MVVM architectural pattern is and how it is used in application development?

The MVVM (Model-View-ViewModel) architectural pattern divides application logic into three parts:

• Model — data model and business logic, responsible for data handling.
• View — presentation layer, UI components that display data to the user.
• ViewModel — intermediary between Model and View, contains presentation logic, transforms model data for display, and handles user actions.

In Flutter, MVVM helps separate UI from business logic, making testing and maintenance easier. The View subscribes to changes in the ViewModel (for example, via ChangeNotifier or Stream), and when data changes, the ViewModel updates the UI.

Example:

• Model: a class with data and loading methods.
• ViewModel: maintains state, processes commands, and updates the Model.
• View: Flutter widgets that listen to the ViewModel and display data.

This approach improves application structure, makes the code more modular, and easier to scale.