title: What is the difference between list and iterator in Python?
body: <p>I am reading the book <a href="http://greenteapress.com/wp/think-python-2e/" rel="noreferrer">Think Python: How to think like a computer scientist</a>, which says that in Python 3.x, <code>dict([list of tuples])</code> returns an <code>iterator</code> instead of a <code>list</code> (as is the case in Python 2.7).</p>
  
  <p>The book did not explain it any further, which has left me confused. In particular, I would like to know:</p>
  
  <ol>
  <li><p>How are iterators and lists different, and</p></li>
  <li><p>What is the advantage of returning an iterator over a list?</p></li>
  </ol>