Header Function PHP

Assalamu'alaikum and selamat sejahtera

Have you ever wonder that a line of code that enable us just go the other website.I meant before this,we just run the php file then it just display as white background and what we can see form address column it just write "http://localhost/...".So,how us to run or execute the php file and then automatically change the address column to any website that we desire.Here is the code:
 
<?PHP
header("Location: http://www.google.com");
?>

run it!so it go to google page ryte?automatically!

N/NOTE:wah!!so fun!!hehe