A WordPress child theme is a sub-theme that inherits all the functionality, features, and styling of its parent theme. Child themes provide a secure method for customizing a WordPress theme without altering the core files of the parent theme. Even when the parent theme receives updates, the changes made within the child theme remain intact and are seamlessly integrated into the updated version. This is why child themes are considered the most reliable and effective approach for modifying an existing theme, as they allow you to override theme templates instead of directly editing theme files.
To create a child theme, you should establish a new directory within your themes directory to house your customized theme. Within this folder, the only essential file is “style.css.” In the header section of the “style.css” file, you can specify the parent theme by including a “template” line within the comment code, where you specify the name of the parent theme. Since this stylesheet is loaded after the parent theme’s stylesheet, it will override any styles defined in the parent theme’s “style.css” file.
To activate the modifications made in the child theme, you need to activate the child theme itself. The parent theme will still retain any functionality that hasn’t been overwritten by the child theme, ensuring a smooth and coherent operation of your WordPress site.