title: Understanding Asynchronous Code in Layman's terms
body: <p>I understand the basic thing about asynchronous-ness: things don't execute sequentially. And I understand there is something very powerful about that... allegedly. But for the life of me I can't wrap my head around the code. Let's take a look at async Node.JS code that I HAVE WRITTEN...but don't truly get.</p>
  
  <pre><code>function newuser(response, postData) {
      console.log("Request handler 'newuser' was called.");
      var body = '&lt;html&gt;' + 
          '&lt;head&gt;' +
          '&lt;meta http-equiv="Content-Type" content="text/html; ' +
          'charset=UTF-8" /&gt;' +
          '&lt;/head&gt;' +
          '&lt;body&gt;' +
          '&lt;form action=" /thanks" method="post"&gt;' +
          '&lt;h1&gt; First Name &lt;/h1&gt;' +
          '&lt;textarea name="text" rows="1" cols="20"&gt;&lt;/textarea&gt;' +
          '&lt;h1&gt; Last Name &lt;/h1&gt;' +
          '&lt;textarea name="text" rows="1" cols="20"&gt;&lt;/textarea&gt;' +
          '&lt;h1&gt; Email &lt;/h1&gt;' +
          '&lt;textarea name="text" rows="1" cols="20"&gt;&lt;/textarea&gt;' +
          '&lt;input type="submit" value="Submit text" /&gt;' +
          '&lt;/body&gt;' +
          '&lt;/html&gt;';
      response.writeHead(200, { "Content-Type": "text/html" });
      response.write(body);
      response.end();
  }
  </code></pre>
  
  <p>Where did response come from again? postData? Why can't I define a variable in this "callback" and then use it outside of the callback? Is there a way to have a few things be sequential then the rest of the program async?</p>