What is a Child Theme?

When I first started creating self-hosted WordPress websites, I had no idea what a child theme was. In order to really understand what a child theme is, we first need to understand what a theme does.

What does a theme do?

A theme dictates what your website will look like from a styling perspective. It determines what elements appear in certain areas and how they look through styling choices like colors and fonts. It’s a silent creative engine that powers your website.

A theme is also responsible for creating a responsive website that looks good on all devices such as tablets, mobile phones, and desktops. This is done through a computer language called CSS, which stands for Cascading Style Sheets — a name that really explains its purpose. I like to think of it as the recipe the computer uses to “bake” and display your website.

This is why each site can look slightly different even when built with the same theme, although some website developers are able to guess what theme or host a site is built with. Good theme “parents” stay updated with things like security fixes and compatibility updates for the latest versions of WordPress.

Why make a child theme?

A child theme allows you to make changes to your website’s design through code modifications without changing the original theme. If you ever make a change that breaks your site, you can simply deactivate the child theme and your website will still work — it just won’t have the same styling you’re used to.

A child theme loads first and then fills in the gaps using the functionality of the main (parent) theme. From a WordPress developer’s perspective, child themes can also be used to carry design features over to a new WordPress website. For example, when I created Marigold, I installed it through a child theme and then made edits to build the Plus version that you see today.

I like to look at it like this: your base theme is your foundation, and your child theme is your personalization layer.

Child themes might feel like an extra step when you’re first building your website, but they’re really just a simple way to protect the work you’ve already done while giving yourself room to grow. You don’t have to be a developer to use one — you just need the willingness to learn as you go. As your website evolves, your child theme becomes a quiet little safety net, helping you customize with confidence while keeping your foundation strong.

Questions? Shoot me an email: katie@katiemcbriendesignco.com.