title: Explanation of CAR, CDR, CADAR, etc
body: <p>Can someone please give me a basic explanation of what the variations of <code>car</code> and <code>cdr</code> do in Scheme?</p>
  
  <p>If I am correct, <code>car</code> will return the first item in the list.  <code>cdr</code> will return a list excluding the first element.</p>
  
  <p>I'm confused on the other variations of these, more specifically things like <code>cadar</code>, <code>caddr</code>, <code>cddr</code>, etc.</p>
  
  <p>Say I have this as a random example:</p>
  
  <pre><code>define X '(a b (c d e))
  
  (car X)
  (cdr X)
  (cadr X)
  (cadar X)
  </code></pre>
  
  <p><code>(car X)</code> would produce <em><code>a</code></em>, <code>(cdr X)</code> would produce <em><code>(b (c d e))</code></em>, <code>cadr</code> would produce <em><code>b</code></em>.  But I don't know how to infer any other variation of <code>car</code>/<code>cdr</code> like <code>cadar</code>.</p>