title: List<?> list = new ArrayList<String>(); List<? extends Object> list = new ArrayList<String>();
body: <pre><code>List&lt;?&gt; list = new ArrayList&lt;String&gt;();
  List&lt;? extends Object&gt; list = new ArrayList&lt;String&gt;(); 
  </code></pre>
  
  <p>These two object we can not add anything in the list, if we will try to add anything it will show a compile time error.</p>
  
  <p>Please tell me where we are using it or what will its use?</p>