title: Interface and generic notations in .NET
body: <p>I am starting with .net and read a couple chapters on generics and interfaces.  I see this in code and am not sure how I should read it:</p>
  
  <pre><code>IEnumerable&lt;IEnumerable&lt;IndexSequenceModel&gt;&gt; model
  </code></pre>
  
  <p>The above is a parameter to a method.  Can someone explain to me what that means?  Thanks.</p>