title: Difference between instantiateViewControllerWithIdentifier and initWithNibName?
body: <p>What is the difference between <strong>instantiateViewControllerWithIdentifier</strong> and <strong>initWithNibName</strong>, other than former is from storyboard and later is not?</p>
  
  <pre><code>UIStoryboard *signupStory = [UIStoryboard storyboardWithName:@"SignupStory" bundle:[NSBundle mainBundle]];
      SignupLoginViewController *signUpVC = [signupStory instantiateViewControllerWithIdentifier:@"SignupVC"];  
  </code></pre>
  
  <p>and      </p>
  
  <pre><code>SignupLoginViewController *signUpVC = [[SignupLoginViewController alloc] initWithNibName:@"SignupLoginViewController" bundle:[NSBundle mainBundle]];
  </code></pre>