Why does require in bitrix work differently than described in the php documentation?

Question

PHP

How does it happen? The template is in local/ , but the path to bitrix/require is still written in it . In addition, header.php is generally located in the bitrix /templates/ directory Did Bitrix somehow change the principle of operation ?
require

<?php
require($_SERVER["DOCUMENT_ROOT"]."/bitrix/header.php");
?>

Answer 1

And you look at the file "/bitrix/header.php" it is his) in the Bitrix folder right lies.
You're a little confused, maybe it's time to sleep)