What is a WordPress Child Theme?
WordPress child themes depend on a parent theme or a theme framework. Child themes borrow all features and appearance of their parent theme and can change them without touching the code of parent theme.
If you add code directly to your theme’s files, then your changes will get overwritten when you update your theme. Child themes solve this problem by allowing you to add your customizations in child theme. This way when you update the parent theme, all your changes will remain intact.
Child themes are more commonly used with WordPress theme frameworks. These frameworks are robust parent themes that offer a solid base for theme developers to build upon.
Installing the WordPress Child Theme
Inside your WordPress admin area, head over to Appearance » Themes page and click on the Add New button.