title: Do I need to always specify the opening <html> tag in HTML5?
body: <p>First Form:-</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
   &lt;head&gt;
       &lt;title&gt;Untitled&lt;/title&gt;
       &lt;meta charset="UTF-8"/&gt;
       &lt;link rel="stylesheet" href="" type="text/css"/&gt;
   &lt;/head&gt;
       &lt;body&gt;
  
       &lt;/body&gt;
   &lt;/html&gt;
  </code></pre>
  
  <p>Second Form:-</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
   &lt;html&gt;
   &lt;head&gt;
       &lt;title&gt;Untitled&lt;/title&gt;
       &lt;meta charset="UTF-8"/&gt;
       &lt;link rel="stylesheet" href="" type="text/css"/&gt;
   &lt;/head&gt;
       &lt;body&gt;
  
       &lt;/body&gt;
   &lt;/html&gt;
  </code></pre>
  
  <p>As I know including <code>&lt;!DOCTYPE html&gt;</code> (if using HTML5) before <code>&lt;html&gt;</code> tag is mandatory, otherwise I may face behaviour issues in my website. (I was told <a href="https://webmasters.stackexchange.com/questions/107728/what-will-happen-if-i-dont-include-the-html-doctype-tag">here</a>)</p>
  
  <p>In the first one, there is no start of <code>&lt;/html&gt;</code> tag, but I have included it in the second one.</p>
  
  <p>I have noticed some of the websites use one of these complexion. It maybe with <code>&lt;html&gt;</code> or non <code>&lt;html&gt;</code>! Even a HTML editor Android app (WebMaster) uses the first one (with no <code>&lt;html&gt;</code>)! </p>
  
  <p>I can't understand, is the <code>&lt;!DOCTYPE html&gt;</code> exact same as <code>&lt;html&gt;</code>, just attached with <code>!DOCTYPE</code>, or both are different!</p>
  
  <p>So, which one is correct? And why that one is correct?</p>