Do you have any tips for the best way to structure partial views?

Hi,
I'm reading about renderSection(), but it seems a bit confusing for me. I don't get its workflow and how it really works. Do you have any tips or know any good tutorial about it?
Thanks.

Views/parent.php

PHP Code:

<h1>Child: <?=$this->renderSection('child')?></h1> 


Views/child-a.php

PHP Code:

<?= $this->extend('parent') ?>

<?= $this->section('child') ?>
AAAAAAA
<?= $this->endSection() ?>

Views/child-b.php

PHP Code:

<?= $this->extend('parent') ?>

<?= $this->section('child') ?>
BBBBBBB
<?= $this->endSection() ?>

Now

PHP Code:

view('child-a') // <h1>Child: AAAAAAA</h1>
view('child-b') // <h1>Child: BBBBBBB</h1> 


Is there something difficult to understand?

View Layouts — CodeIgniter 4.1.7 documentation
https://codeigniter4.github.io/userguide...youts.html

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Is

PHP Code:

<?= $this->endSection() ?> necessary?