title: OrderByDescending() per MSDN, what on earth does this mean?
body: <p>Can someone please help be take apart the elements here and help me understand what they are?</p>
  
  <pre><code>public static IOrderedEnumerable&lt;TSource&gt; OrderByDescending&lt;TSource, TKey&gt;(
      this IEnumerable&lt;TSource&gt; source,
      Func&lt;TSource, TKey&gt; keySelector
  )
  </code></pre>
  
  <p>What is TSource and TKey? What is a keySelector? What the heck is an IOrderedEnumerable?</p>
  
  <p>What does Func&lt;> do??</p>
  
  <p>Why is MSDN so cryptic?</p>