title: Node.js and socket.io confusion
body: <p>I so often see titles like "Node.JS + socket.io tutorials." Even in the Node.js Beginner book I've purchased, it tells me to download socket.io so I'm getting really confused.</p>
  
  <p>What's the difference between them? Why can't I code my applications just with Node.JS "OR" Socket.io? If I can code, why do people socket.io plus node.js in titles?</p>
  
  <p>I'm really confused so any kind of replies would be appreciated.</p>