Override template files in child theme
In your child theme's folder create a subfolder called &quot;templates&quot;. In this folder you should store your own templates. Just copy the system's (or parent theme's) template to your folder and modify it.
Further on, you can create more special templates, i.e. not only node.html.twig but also node--blog.html.twig.
Finally, switch on twig debugging, then you will get comments in your html like this:
&lt;!-- THEME DEBUG --&gt;
&lt;!-- THEME HOOK: 'block' --&gt;
&lt;!-- FILE NAME SUGGESTIONS:
   * block--bootasde-branding.html.twig
   x block--system-branding-block.html.twig
   * block--system.html.twig
   * block.html.twig
--&gt;
&lt;!-- BEGIN OUTPUT from 'themes/bootstrap/templates/block/block--system-branding-block.html.twig' --&gt;

Then you always know which template was finally taken.