Hierarchy of iOS App UI

Question

I am getting confused reading about CALayers, UIViews and View Controllers. Can someone explain the relationship each of those have to each other (and include anything I might have missed?).

I am particularly interested in a View that may have more than one layer. Does that mean the the View Controller has multiple UIViews or that the UIView has more than one CALayer? Or, does the UIView have another UIView subview?

Thanks for the help guys.

Edit: I guess I should have mentioned I am going to be setting these guys up programmatically, which is why I need to actually understand the relationships instead of relying on IB to do all the heavy lifting for me.

Answer 1

Have you read

http://tuvix.apple.com/library/ios/#documentation/Cocoa/Conceptual/CoreAnimation_guide/Articles/LayerTreeHierarchy.html ?