Explain the main stages of development and operation of an application from launch to completion.

Main stages of the Flutter application lifecycle:

1. Application startup: At the entry point (main()), runApp() is called, which initializes the root widget of the application.

2. Building widgets: Flutter constructs the widget tree, starting from the root, calling the build() method for each.

3. Rendering UI: Based on the widget tree, a tree of elements and render objects is created, responsible for displaying on the screen.

4. Event handling: User actions (presses, gestures) are processed through the event system and trigger state updates.

5. State update and re-rendering: When the state changes, setState() is called, leading to a re-invocation of build() and UI update.

6. Shutdown: When the application is closed, resources are released, and cleanup methods (e.g., dispose()) are called in widgets.

Thus, Flutter manages the UI through a reactive model, where changes in state automatically reflect on the interface.