title: difference between Thread and Handler
body: <p>Can somebody tell me the deference between Thread and Handler? When we use Thread and when we use Handler?</p>
  
  <p>I have two code in my project , But I can't understand them.</p>
  
  <pre><code>final Handler handler =  new Handler()
  {
      @Override
      public void handleMessage(Message msg)
      {
          //  Do SomeThings
      } 
  };
  </code></pre>
  
  <p>And </p>
  
  <pre><code>private class readThread extends Thread
  {
      Handler mHandler;
  
      readThread(Handler h){
          mHandler = h;
          this.setPriority(Thread.MIN_PRIORITY);
  
      }
  
      @Override
      public void run()
      {
          //  Do SomeThings
      }
  }
  </code></pre>
  
  <p>And in another method call the handler like this </p>
  
  <pre><code>read_thread = new readThread(handler);
              read_thread.start();
  </code></pre>
  
  <p>Which one run first?? Can somebody explain me?</p>