title: IHttpActionResult difference between returning item, Json(item) and Ok(item)
body: <p>In ASP.NET WebApi 2, what is the difference between the following:</p>
  
  <pre><code>public &lt;IHttpActionResult&gt; GetItem(Guid id)
  {
      // ... code ..., Item result = ....
      return result;
  }
  
  public &lt;IHttpActionResult&gt; GetItem(Guid id)
  {
      // ... code ..., Item result = ....
      return Json(result);
  }
  
  
  public &lt;IHttpActionResult&gt; GetItem(Guid id)
  {
      // ... code ..., Item result = ....
      return Ok(result);
  }
  </code></pre>