# Activity requirements and compatibility

> Understand the characteristics and compatibility of the Activity application entry point.

Activity was originally the only application entry point that Unity supported. As a result, it's highly stable across most scenarios and is compatible with the majority of Unity features.

## Plug-in compatibility

If you use Activity, your application player loop runs on a Java thread. This means that you can call Java APIs like [`myLooper`](https://developer.android.com/reference/android/os/Looper#myLooper\(\)) from plug-ins.

## Frame synchronization with the Choreographer

If you use Activity, Unity uses the Android Java [`Choreographer`](https://developer.android.com/reference/android/view/Choreographer). This helps you to understand how frame synchronization occurs in your application.

## Additional resources

* [The GameActivity application entry point](/engine/6000.3/manual/platform-specific/android/developing/application-entries/game-activity.md)
* [Extend the default Unity activity](/engine/6000.3/manual/platform-specific/android/developing/application-entries/activity/unity-player-activity.md)