title: How to run a flask application?
body: <p>I want to know the correct way to start a flask application.  The docs show two different commands:</p>
  
  <pre class="lang-none prettyprint-override"><code>$ flask -a sample run
  </code></pre>
  
  <p>and</p>
  
  <pre class="lang-none prettyprint-override"><code>$ python3.4 sample.py 
  </code></pre>
  
  <p>produce the same result and run the application correctly. </p>
  
  <p>What is the difference between the two and which should be used to run a Flask application?</p>