title: What is the difference between various web service implementations
body: <p>I am new to web services programming. Recently I started learning web services but there I came across various specifications like:</p>
  
  <ol>
  <li>REST</li>
  <li>JAX-WS</li>
  <li>JAX-RPC
  etc.</li>
  </ol>
  
  <p>Kindly update me that does these technologies occur in parallel or some are old versions and others are new versions of the same.</p>
  
  <p>Also do I need to follow a hierarchy while learning these or I could start with any one randomly.</p>
  
  <p>Thanks in advance</p>