A child theme is a safe layer on top of your main WordPress theme where customizations live. It lets you change how your site looks without those changes getting wiped out the next time the main theme updates.
Also known as: Child theme customization
In plain English
Your WordPress theme is the design layer - and theme authors update it regularly. If you edit the theme's files directly, every update overwrites your changes. A child theme is a separate, small theme that inherits everything from the main one and holds only your customizations on top.
Why it matters for your business
It's the difference between customizations that survive updates and ones that silently vanish the next time the theme patches a bug. Any site with real custom code should be running a child theme.
When you'll run into it
Whenever you need custom CSS, template tweaks, or PHP changes to how the site looks or behaves - set it up before making the first customization, not after.
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