title: CreateItem vs ItemGroup
body: <p>What is the difference between creating an item inside a target like this:</p>
  
  <pre><code>&lt;Target Name="DoStuff"&gt;
      &lt;CreateItem Include="@(IntermediateAssembly)" &gt;
          &lt;Output TaskParameter="Include" ItemName="FileWrites"/&gt;
      &lt;/CreateItem&gt;
  &lt;/Target&gt;
  </code></pre>
  
  <p>and like this:</p>
  
  <pre><code>&lt;Target Name="DoStuff"&gt;
      &lt;ItemGroup&gt;
          &lt;FileWrites Include="@(IntermediateAssembly)" /&gt;
      &lt;/ItemGroup&gt;
  &lt;/Target&gt;
  </code></pre>
  
  <p>When would you use one or the other and why?</p>