title: Difference between @property and variable within interface declaration
body: <p>What's the difference between putting a variable inside of the <code>@interface{}</code> declaration in a header file, and putting in a <code>@property</code> after that declaration?</p>
  
  <p>E.g.,</p>
  
  <pre><code>@interface GameCenterManager : NSObject
  {
  GKInvite* pendingInvite;
  }
  @end
  </code></pre>
  
  <p>as opposed to</p>
  
  <pre><code>@interface GameCenterManager : NSObject
  @property (weak, nonatomic) GKInvite* pendingInvite
  @end
  </code></pre>