I would elaborate it as follows :
In what order are the different objects and nib files instantiated/initialized ?
My understanding is as follows:
1) UIMainApplication function loads the main .nib file specified in info.plist.
2) This .nib file instantiates the Delegate object.
3) When the appDidFinishLoading method runs, it generally initializes the UIViewController object.
In general, a .nib file instantiates the objects connected to it and the objects instantiate/load the .nib file they have a IBOutlet in.
If this is too complex to explain here, please point me to an appropriate article.
Thanks.