php how to see data that was posted code example

Example: php post

<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
  Name: <input type="text" name="fname">
  <input type="submit">
</form>
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  // do logic
  $name = $_POST['fname'];
}
?>