What does the first few lines in android really mean?

Question

I mean .. these lines.....

public class FindBeerActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_find_beer);
}
}

Answer 1

https://stackoverflow.com/questions/6953653/new-to-android-app-programming-so-need-this-explained

Answer 2

Activity comprises the visual components (”Views”) for one screen as well as
the code that can respond to user events on that screen. Almost every application
has at least one Activity class.

The oneCreate() method gets invoked when the activity is instantiated in
response to e.g., you clicked on the app's Icon in the Home Screen.