title: Tensorflow : What is the relationship between .ckpt file and .ckpt.meta and .ckpt.index , and .pb file
body: <p>I used <code>saver=tf.train.Saver()</code> to save the model that I trained, and I get three kinds of files named:</p>
  
  <ul>
  <li>.ckpt.meta </li>
  <li>.ckpt.index</li>
  <li>.ckpt.data</li>
  </ul>
  
  <p>And a file called:</p>
  
  <ul>
  <li>checkpoint</li>
  </ul>
  
  <p>What is the connection with the <strong>.ckpt</strong> file? </p>
  
  <p>I saw someone saved model with only .ckpt file, I don't know how to make it. 
  How can I save model as a .pb file?</p>