html what does title: do code example

Example 1: html title

<head>
  <title>My page title</title>
</head>
<script>
  document.title = "My new title";
</script>

/*Title popup*/

<body>
  <p title="Popup here">hover me!</p>
</body>

/*Tab title*/

<head>
  <title>This is the tab title</title>
</head>