title: CGContextRef vs NSGraphicsContext
body: <p>I just started learning OSX programming, and I've stumbled upon a problem where I don't know if I should use <code>CGContextRef</code> or <code>NSGraphicsContext</code>.</p>
  
  <p>What is the difference?</p>
  
  <p>I barely know the difference between CG or NS [and how they relate to cocoa] (I've tried googling to no avail)</p>
  
  <p>Could anybody shed some light on when I would want to use either, or what the key differences are?</p>
  
  <p>I'd take a link to an article, even.  I just can't find anything from my web searches.</p>
  
  <p>I know I'm asking a lot of questions in one, so thanks in advance!</p>