title: Cocoa versus Cocoa Touch - What is the difference?
body: <p>I am learning iOS development in Objective-C, and I have found a lot of code examples.</p>
  
  <p>Some of them, though, say that they are only for Mac OS X (not iOS).</p>
  
  <p>Can someone please explain to me what is the difference between Cocoa and Cocoa Touch (at a library level), so that I know what code will work and what will not work?</p>