title: Why do we leave some structure variables out of the curly brackets?
body: <p>I'm trying to understand <code>struct</code> in C. I couldn't get the idea about this definition below. Why do we leave <code>aCard</code>, <code>deck[ ]</code> and <code>*cardPtr</code> out? What is the difference between including them in and leaving them out?  </p>
  
  <pre><code> struct card {
      char *face;
      char *suit;
   } aCard, deck[52], *cardPtr;
  </code></pre>