What is the role of the AndroidManifest.xml file in a project and why are its main components usually declared there?

The AndroidManifest.xml file is the main configuration file of an Android application, which describes the structure and components of the app for the Android system.

It declares:

• Application components: activities (Activity), services (Service), broadcast receivers (BroadcastReceiver), content providers (ContentProvider).
• Permissions required by the app to access device resources.
• Intents and filters for components, defining what actions they can handle.
• Minimum and target SDK versions.

Main components are declared in the manifest so that the system knows about them and can correctly launch and manage them. Without declaration, components will not be recognized by the system and cannot function.

Example of declaring an activity:

<activity android:name=".MainActivity">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>