getWritableDatabase is one of the methods of the Android's SQLiteOpenHelper class which returns a reference to a SQLiteDatabase.
The getWritableDatabase is a method of the SQLiteOpenHelper class, from the Android platform, used to retrieve a reference to a SQLiteDatabase in which the user can insert data. Calling this method will either open an already created database or will trigger the creation of the database if one doesn't exist. Executing this method may take a long time so it's recommended to not call it on the main UI thread.