Checking for page referer in php. Wordpress redirect or header refresh

referer.php

   <?php
    //check for refering page to switch content based on referrer
    $referrer = $_SERVER['HTTP_REFERER'];
    if ($referrer == 'http://url.com' or $referrer == 'http://url-2.com') {
        	//Matches YES!
		
		 } else { 
		 	//Matches NO!
		 header( 'Location: http://www.url.com/no-soup-for-you/' ) ;

		  } ?>
		 
		 
		 

I don't understand of what it will do if the referre is correct

@MrDoxxer2 if the page that redirected you to the referer.php is equal to url.com then it does something. Otherwise redirect it to something else.