title: Point of using NSPersistentStoreCoordinator?
body: <p>In the Core Data lecture from <a href="http://www.stanford.edu/class/cs193p/cgi-bin/drupal/" rel="noreferrer">Stanford 193P</a> iPhone course on iTunes, the instructor coded up a sample project with Core Data without using <code>NSPersistentStoreCoordinator</code> and loading it with a <code>NSManagedObjectModel</code>. But in looking at other code samples and the Big Nerd Ranch book on iPhone development, they are creating a <code>NSManagedObjectModel</code> and PersistentStoreCoordinator and setting up the <code>NSManagedObjectContext</code> that way.</p>
  
  <p>My question is what is the purpose of doing it this way, and what are the pros and cons of both approaches?</p>