title: What is the reason behind having a StatelessWidget?
body: <p>I have noticed that, we can use a <code>StatefulWidget</code>to build any part of the UI without worrying about the state.</p>
  
  <p>What I am asking is simply, what are the reasons behind having a <code>StatelessWidget</code> in the first place, when we can build any UI class as a <code>StatefulWidget</code> whether we are going to provide it with a <code>State</code> or not?</p>
  
  <p>Does using a <code>StatefulWidget</code> comes with an additional cost that makes creating a <strong>stateless</strong> UI easier/faster/better using a <code>StatelessWidget</code>?   </p>
  
  <p>When I read the docs, I can not exactly point out the difference between using <code>StatelessWidget</code> and <code>StatefulWidget</code> when describing stateless UI components. <a href="https://docs.flutter.io/flutter/widgets/StatelessWidget-class.html" rel="noreferrer">It is even recommended to</a> </p>
  
  <blockquote>
    <p>Consider refactoring the stateless widget into a stateful widget so
    that it can use some of the techniques described at StatefulWidget...</p>
  </blockquote>