Default activity

I am reading a tutorial and the default activity is a class that extends another, and all that it has is an overriden method. How does the application work since it doesn't do anything el开发者_如何学编程se? I am very confused!

The parent class Activity handles everything for you.

Its a framework. By extending Activity, your activity inherits basic functionality. If you want to add/change something, you need to override its methods. But even though, not all application functionality is inside your activity. You are basically writing components. The Android plattform will use them. This is why you need a reference to them in your Manifest file.

Btw; no offense, but if you demand more specific answers, you should specify your question first.