I using some HTML my website but I confused using slash

Question

What is correct HTML 1 or 2.

HTML 1

<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
<link rel="apple-touch-icon" sizes="57x57" href="https://yeuteu.com/static/icons/apple-icon-57x57.png">

HTML 2

 <meta charset="utf-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no"/>
<link rel="apple-touch-icon" sizes="57x57" href="https://yeuteu.com/static/icons/apple-icon-57x57.png"/>

Answer 1

The short answer is: both.

HTML allows short-tags, such as <img src="/image.png" alt="An Image">.

All valid short tags can be written XML style with a self-closing slash: <img src="/image.png" alt="An Image" />. They are equivalent in HTML.

If you were authoring an XHTML document (nobody is these days), the self-closing slash would be required.