That's because we haven't really discussed it. The reason we have not discussed the behind-the-scenes details is because we don't need to know them. As long as we override the required methods, as we just saw, everything will work. This is how BaseAdapter and most other classes we use are meant to be, the hidden implementation with public methods to expose the necessary functionality.

It is true that there are more details for BaseAdapter (and almost every class that we use in this book) that we don't have the space to discuss. It is good practice to read the official documentation of the classes you use. You can read more about BaseAdapter at http://developer.android.com/reference/android/widget/BaseAdapter.html.