title: What does the question mark in Java generics' type parameter mean?
body: <p>This is a small snippet of code taken from some of the examples that accompany the Stanford Parser.  I've been developing in Java for about 4 years, but have never had a very strong understanding of what this style of code is supposed to indicate.</p>
  
  <pre><code>List&lt;? extends HasWord&gt; wordList = toke.tokenize();
  </code></pre>
  
  <p>I'm not worried about the details of the code.  What I'm confused about is what exactly the generic expression is supposed to convey, in English.</p>
  
  <p>Can someone explain this to me?</p>