title: How to relate UIKit, Core Image, Quartz 2D, and the various frameworks in iOS?
body: <p>It is clear to me so far that UIKit is on top of Core Graphics and Core Animation, and what Core Graphics and Core Animation can do, UIKit has some higher level method to do them as well.</p>
  
  <p>How about the other layers, Core Image, Quartz 2D, Quartz, Quartz Core, Quartz Graphics, Core Video, Cocoa Touch, Core Motion.  How do they relate to each other?  (is there a good diagram that depicts where they belong in the iOS precisely?)</p>